Re-Barreling/Re-Chambering my K31 Swiss

[HollowPoint]

It's been a long time coming. I've dreamed of doing this since bringing this rifle home.

Why? There are many reason I can come up with but, to anyone asking "Why," no reason is good enough. Lets just say I'm tweaking an already very-good rifle to my own preferences.

On Wednesday I had the day off so I made an action-wrench shaped specifically for the K31 receiver. On ThanksGiving morning I used this action-wrench to remove the barrel from the receiver and I was surprised to see how close the tolerances were of this old Swiss rifle. For being a rifle built pre-CNC, it is really surprising to see this level of accuracy.

From the measurements I was able to get off of the receiver, it looks like "Truing-The-Receiver" won't be necessary. I'll have to wait till I get farther along to do double check though.

The barrel threads appear to be metric. I say this because my standard thread pitch gauge had nothing on it that would fit the threads on the barrel tenon. I'm presently waiting on my newly ordered metric thread pitch gauge to arrive. I'll be taking lots of pics as I move along with this project; and I'll be doing this job my own way.

I have to state up front that I'm not a gunsmith and I'm not a machinist. I'm sure there are several ways to go about this but as I've just stated, I'm doing it my way; which may or may not be the right way.

I generally don't post my projects any more until after I've completed them. This is due to the ever present Trolls, Nay-Sayers and well-meaning Dream Killers; as well as the Self-Appointed-Experts. Few things are worse than one of the above trying to tell you how to do something when we know that it's not likely they've ever undertaken such a project themselves. Insight from those with hands-on experience is always welcome and appreciated; negatives from the Self-Righteous and All-Knowing among us, not so much.

Following is the list I made pertaining to this project. I laid it out for myself. It's in the general order that I'll be approaching this project. And, I forgot to mention; I'll be re-chambering to 6.5 x 55 Swedish.

I'll be back with updates as they happen.

HollowPoint

K31 Re-Barrel Project


Materials needed:
(1) Steel for Making Action/Receiver Wrench--Two Large Bolt/Washer/Nuts Done
(2) Steel Tube for Bolt/Receiver Truing Fixture--Eight Bolts/Spiders Done
(3) Wood for Barrel Vice Done
(4) Drill Rod for Truing Receiver Done
(5) 4140 Rod for Making Barrel Nut and Recoil Lug--2" diameter 4" long Done
(6) Dykem Layout Dye Done
(7) Barrel--Chamber Reamer--Range Rod--Go Gauge--Loading Dies--Brass--Bullets Done or On The Way


Measurements needed With Barrel Still On The Receiver:


(1) Back Of Receiver to the Breech Face =_______ Done
(2) Back Of Receiver to the Cam Face =_______ Done
(3) Back Of Receiver to the Case-Head =_______ Done


Measurements Needed With Barrel Removed From Receiver:


(A) Front of Receiver to the Receiver Lugs =_______Done
(B) Front of Receiver to the Bolt Face =_______Done
(C) Front of Receiver to the Bolt Lugs =_______Done


Steps In Sequence:


(1) Check Bolt-Lug Contact Before removing Barrel (Lap Lugs if Needed) Done
(2) Remove Barrel from Receiver Done
(3) True Up Receiver, Receiver-Threads and Bolt-Face Done
(4) Measure New Receiver-Threads for New Tenon Dimensions Done
(5) Index Barrel in Lathe and Cut Outside Tenon Dimensions Had To Go To Plan-B
(6) Cut Threads Done
(7) Short Chamber With New Chamber Reamer Done
(8) Dykem Barrel Tenon, Screw into Receiver, Mark Extraction Notches and Cam Position Had To Go To Plan-B Done
(9) Make Cam Template with aluminum sheet metal Done
(10) Remove Barrel from Receiver and Cut Extraction Notches and Barrel-Cam
(11) Make Barrel Nut and Recoil Lug Had To Go To Plan-B
(12) Assemble and Head-Space
(13) Make New Scope Mount Done
(14) Disassemble and Powder Coat Flat Black then Reassemble. Done (I Powder-Coated while I was waiting for the new barrel to arrive; also sanded and refinished the stock.)
(15) Safety/Function Testing Done--Project has now been completed and Proof-Tested successfully.

[Wolfer]

Well I don't consider myself as a Troll, nay-sayer or dream killer and I'm not an expert at anything. I am though a pretty handy feller who often thinks outside the box. I believe I recognize a kindred spirit.

While talking to a co-worker about my latest 34-57 project he asked why, I replied that because I could.

I look forward to seeing this project unfold.

[skeettx]

6.5x55 COOL!!
Whose barrel?
Thanks for posting
Mike

[gzig5]

Curious as to how you plan on cutting the extraction cam surfaces in the rear face of the new barrel? Definitely post pics.
Every re-barreling of the K31 that I am aware of being done outside of at the factory in Switzerland, has utilized the old barrel stub bored out to fit a new barrel in order to retain these surfaces because of the difficulty in reproducing them.

[Outpost75]

Do you have plans for the pull-off K31 Swiss barrel? If you keep the breech for a stub, that is OK, my plans for it would be to have John Taylor fit the remainder to an H&R .44/.410 shotgun receiver and chamber it in .30-30 for a light walking rifle.

[HollowPoint]

Thank you so much Wolfer:

I'm afraid I come off as abrasive and end up turning people off when I pre-empt my posts in such a way as I have but I've had more than my share of negative comments, opinions and suggestions on alot of my previous projects (not so much on this forum but on the internet in general) that I tend to put up a shield without thinking what an offensive turn off it can be.

My apologies to everyone for this character-flaw on my part but, I can't help but think of all those potentially great ideas that have been stifled before they're even attempted simply because of a well-meant but misspoken word.

I know I'm not the only dreamer here. I also know from my research into the subject of re-barreling the K31 rifle that I'm not the only one who has considered doing the same with their K31's as well. I hope to be informative enough to dispel the deeply entrenched myth that the K31 rifle is to hard for the home gunsmith to re-barrel/re-chamber; it's to complex, it's to expensive, it's not worth the trouble, etc, etc, etc.

Having taken mine completely apart, it doesn't look all that complex to me. Perhaps that's one of the benefits of being ignorant. If I knew better I might not ever accomplish anything. It does have some angles that other rifles do not have but, most of those angles will not require altering of any kind.

For example: By blacking them out with a sharpy, I checked the angled contact surfaces of the Bolt-Lugs as they rubbed against the Receiver-Lugs just to see how evenly they were making contact. Looking at them with the naked eye, they appear to be perfectly even. The wear marks on the Receiver-Lugs show the same even wear. Oddly enough, the faces of the Receiver-Lugs are machined at an angle matching the angle of the Bolt-Lugs so it's a good thing they're wearing evenly. It means that I don't have to alter them to get them to contact evenly.

If I had to even them out myself, I'm really not sure how I'd go about it. I'm sure I'd think of something but, thank God I don't have to.

One of the things I'm having to do now with this project is build specialty jigs in order to do some of the operations that will be needed here. I've already made my Action-Wrench and it worked like gang-busters. Next I'll be putting together my Receiver-Truing-Jig followed by the Specialty-Truing-Rod I'll be using to check to see if the face of the Receiver will need to be trued. From some of my preliminary measurements, I found that the receiver face may not need truing.

Well, I'm starting to ramble on without saying a whole lot that you probably don't already know. Thanks for the encouragement. I'll be back as I get farther along. I've already taken a few pictures. I just have to edit them for posting on the web.

HollowPoint

[HollowPoint]

Do you have plans for the pull-off K31 Swiss barrel? If you keep the breech for a stub, that is OK, my plans for it would be to have John Taylor fit the remainder to an H&R .44/.410 shotgun receiver and chamber it in .30-30 for a light walking rifle.

My original plans for the take-off barrel is to keep it until I reach the end of this project. I'm fairly confident I can pull this off if I take my time and remain meticulous about each step in the process. When I've completed everything and confirmed that it was a success, I'll then consider selling the barrel to recoup some of the expense of this project.

Right now the barrel has the Rear-Sight fixture removed so it's just a naked barrel. It actually came loose while I was removing the barrel from the receiver. I think it's just soldered into place at the factory. It's been my plan all along to re-barrel without having to cannibalize my existing barrel. As a fail-safe, and if worse comes to worse, I can reinstall it back onto my receiver until I can raise the spare change to try it again.

skeettx/Mike asked, "Who's Barrel?" If you mean what barrel brand I'll be using, I plan on using a #4 contour Shilen barrel. I'll have to order one with some added diameter on the chamber end of the barrel blank just so there's enough meat to cut my threads. If I read it correctly, Shilen's website states that I can order a barrel with "Added Diameter" on any part of the barrel blank. I'll be contacting them next week to confirm this.

I'll have to wait and see.

HollowPoint

[M-Tecs]

I haven't re-barreled any of mine. Most choose not to cut extraction cam surfaces and go the barrel stub route.

LPR has an excellent reputation. www.lprgunsmith.com/K31_rifles.htm

[HollowPoint]

I haven't re-barreled any of mine. Most choose not to cut extraction cam surfaces and go the barrel stub route.

LPR has an excellent reputation. www.lprgunsmith.com/K31_rifles.htm (http://www.lprgunsmith.com/K31_rifles.htm)


Yes, I've heard good things about this gunsmith. In fact, I've contacted him myself on a couple of occasions while doing research into this re-barreling job. On both occasions he was kind enough to reply. To me, that's a sign of integrity.

Virtually every time I went online to try to dig up more new information on this project, Larry at lrpgunsmith.com came up. That not only speaks of his expertise on this subject but also to the near total lack of general gunsmithing information about this particular rifle.

At first I thought it was because those who did know just didn't want to share, but now I see that all of those things you read on the internet about this rifle being so hard to work on is just deeply entrenched hear-say; so much so that it appears that very few even bother trying.

Who knows, I may find out the hard way that they were all correct in their assessment of the difficulties of working on K31 rifle barrels. On the other hand.........


HollowPoint

[ratboy]

Well I don't consider myself as a Troll, nay-sayer or dream killer and I'm not an expert at anything. I am though a pretty handy feller who often thinks outside the box. I believe I recognize a kindred spirit.

While talking to a co-worker about my latest 34-57 project he asked why, I replied that because I could.

I look forward to seeing this project unfold.

i built a 357 maximum marlin lever just because i thought i needed to.
i think a 6.5 k31 sounds like enough fun i might have to buy another rifle to take apart.
i think it is probably a good thing we all live so far apart. i dont want to know what kind of mayhem we would get into as a group.
:-)

[HollowPoint]

Here are a few pics of my K31 after disassembly.

Right now I'm working on my Receiver-Truing-Jig. Once I get that done I can check the receiver to see if it will need to be trued to the axis of the bore. I'm hoping it won't but if it does need it, I'll be prepared for it.

After that I can order my new barrel and while I'm waiting for it to show up I'll move on to laying out the shapes of my Barrel-Nut and Spacer.

The "Spacer" will sit between the Barrel-Nut and the front receiver face. It will be the attachment point for my scope mount.

Previously, the front of my scope mount was attached within the factory rear sight trough using the same cross-pin and an additional screw. WIth the factory rear sight trough gone, I needed to come up with another way to secure my scope mount to the front of the receiver. I don't want to drill any more holes in my receiver so, the "Spacer" is what I came up with. I'll have to fabricate it before I can show it to you but, now I'm getting ahead of myself.

Enjoy the pics. Hopefully they'll give you a good idea of what I'm working with. I'll be back.


HollowPoint

[ratboy]

neat.

:popcorn:

[Plate plinker]

No guts no glory my dad always says. Good luck.

[HollowPoint]

Thanks Plinker:

I appreciate that. I'm not really looking for "Glory." I'm just wanting to dispel some of those K31 Old-Wives-Tales. Although, some of those Old-Wives-Tales are so deeply entrenched that I'm sure they'll live on no matter how much proof is offered up to dispel them.

It's kind of like the "Climate-Change" thing; for lack of a better analogy.

To anyone who's reading this right now. Do an internet search on the subject of Re-barreling a K31. What you'll get is a whole lot of the same thing. In many cases, word for word repetition to those that have inquired about how it's done or the feasibility of doing it themselves.

Also; the older I get, the less I like the feel of recoil on shoulder. I think that going from 7.5x55 to 6.5x55 will help a little in that regard. And yes; I know that I could simply power down my existing loads and save myself alot of work and potential failure but, that just skirts around the point of this whole project. I want to do it myself to prove to myself that I can do it; and to prove to others that it can be done by them as well.

HollowPoint

[EDG]

:popcorn:

[Wolfer]

When I was young say 20 or so I traded guns some. Often buying something that needed work. Fixing it up and reselling it. I wanted to build a rifle on a Mauser action. I bought a pistol in a cigar box with no two pieces together for $20.00 Supposedly it was all there, it wasn't. I had to make the hand and spring and time everything. Also had to make grips for it.

Traded it and $12.00 for a 98 Mauser in 7.65 argentine. Now I was ready to build my rifle but I didn't know where to start. Everyone I talked to said the same thing. Forget about it and leave that stuff to people who know what their doing. My question was how do people who know what their doing learn what their doing. There was no Internet back then and finding a place to start was slow. Eventually I got some books on the subject and met a gunsmith who was willing maybe even eager to help me along.

Once I built my first rifle myself I realized I could have done this years ago but I listened (somewhat) to all the nay Sayers and dream killers out their.
I made some mistakes on my first one and on my second but any school you go to charges a tuition. The school of hard knocks is no different.

I have found there's a direct relationship between how much your tuition costs and how much you learn!
Woody Roberts

[skeettx]

General question, does the action have the capacity of conversion to 243 Win or 6mm Rem?
Is the 57mm of the 6mm Rem ok with the shorter bullets overall length?

[HollowPoint]

General question, does the action have the capacity of conversion to 243 Win or 6mm Rem?
Is the 57mm of the 6mm Rem ok with the shorter bullets overall length?

This most likely won't answer your question directly but it may give you a general idea of the answer you're looking for.

I chose to re-chamber to 6.5x55 because it's a cartridge similar in dimension and lower in Maximum-Average-Pressures than the original 7.5x55 Swiss cartridge. I wanted to make sure that the K31 action could handle the pressures of this or any cartridge I originally had in mind. As it turns out, the K31 action is strong enough; so much so that I should be able to safely reload my ammo to the level of the ammo built for more modern rifle actions.

It turns out that the Hammerli company has used the K31 receiver to offer rifles in calibers up to 300 H&H. On the Swiss-Rifle forum there's a guy who uploaded copies of the original advertisements from Hammerli. Some of the other calibers that have been chambered using this action are the 308 Winchester, 3006, 300 Win Mag and others I can't recall right now. If the pressures are within the maximum pressures of the most powerful of these, I suppose they're within the safety margin of this action. I would suggest doing additional research just to verify this before undertaking such a re-chambering though.

Incidentally; conversions like the 300 Win Mag and the 300 H&H rendered this action a single shot rifle due to the length of the cartridges.

HollowPoint

[Der Gebirgsjager]

A very interesting project. I doubt if the receiver started as a casting. The casting technology wasn't advanced enough to permit it during that time period. Cutting the cam surfaces seems to be the challenge. The Swiss did it, so it can be done. Just reading between the lines I gather that you have a lathe. Do you have a mill? Good photos!

[Cap'n Morgan]

Looking forward to see this project finished. Excellent choice in caliber...

If you can't wait for the metric thread gauge to show up; just screw the barrel into the receiver, unscrew it exactly five (or six, or seven) turns, measure the gap & multiply with 25.4, then divide with the number of turns - and you have the metric pitch.

The receiver was probably die forged close to size to minimize machining, but there was no doubt an awful lot of handwork and filing involved.

[HollowPoint]

A very interesting project. I doubt if the receiver started as a casting. The casting technology wasn't advanced enough to permit it during that time period. Cutting the cam surfaces seems to be the challenge. The Swiss did it, so it can be done. Just reading between the lines I gather that you have a lathe. Do you have a mill? Good photos!


I'm sure you're right about the casting. It's just that when I look at this receiver and all of its contours; both inside and outside, it's hard for me to picture exactly how they'd go about milling such a receiver. If anything, it must have taken many, many additional post-machining steps and alot of hands-on work to get it to its finished stage. The "Die Forging" mentioned by the good Cap'n Morgan might very well be the way they went about it. I'd never heard of that till just now.

I suspect the cam surfaces in the receiver started out flat just like on most conventional rifle receivers. The Swiss must have come up with some type of jig to grind them to the desired angles.

I do own a small Grizzly 4003-Gunsmithing lathe and a small Tormach 770 CNC mill with a forth-axis feature. Photos of this same machinery can be seen on the internet by just googling them. What I don't have is enough free-time to play around with these toys as I'd originally hoped when I took possession of them.

I dream of being able to retire some day and playing around with these machines to my hearts content.

HollowPoint

[HollowPoint]

NAY SAY...... OK joke over with ..
6.5x55 Excellent choice in my opinion Hollowpoint, Very interesting project.

Look forward to you completing this one Wish you the best of luck
Mike

Thanks Mike:

I thought I'd be able to finish up the last of the work on my one-off specialty K31 Receiver-Truing-Jig but when I got to the hardware store to pick up the appropriately sized nuts and bolts for the "Spider-Setup" they only had five out of the eight nuts that I needed to get the job done. Because I have a full work schedule next week, it may not be till next Saturday till I can weld it together.

Due to the shape of the K31 receiver, I had to cut a channel near the rear of the Jig in order to accommodate the trigger housing. If it weren't for that trigger housing hanging down from the bottom of the receiver I could just use a thick-walled 3" diameter cylindrical eight-inch section of pipe like they use for truing up Remington actions but, not so on this K31.

Another thing is that the Drill-Rod I intended to use to act as my indexing rod was not the correct diameter. I have to return it and go with Plan-B on this part of the project. It turns out that the Bolt on my K31 has an outside diameter that is just a thousands-or-so smaller than a 55/64" Drill-Rod. The actual diameter of this particular Drill-Rod is listed as being just a hair larger than the diameter of my Bolt. I figured that because of this I could simply slide it into my Receiver for a snug fit. It didn't turn out that way. The Drill-Rod was perfectly straight but the diameter was actually the exact same diameter as the Bolt. I needed it to be the size that it was listed at in order to work. As it was it fit to loosely to get an accurate reading on the center-line of the receiver.

I'm learning as I go along; and once I get it all done, it's not likely I'll ever need to use any of these home made specialty tool ever again; unless I were to buy another K31 somewhere down the line. I think this is an example of the "Tuition" or the cost of learning that was mentioned in one of the previous replies to this post.

HollowPoint

[HollowPoint]

I think I'm on a roll; but that Roll ended at about two-o'clock today. My scheduled appointment showed up real late and while I was waiting I did some work on my K31 project.

Here are a few more pics to give you all an idea what I was attempting to describe in my previous posts.

All I need is a little more free time and I'll be able to setup this Receiver-Truing-Jig on the lathe to see what kind of run out the Receiver has. If it's less than one-thousands of an inch I'm just going to leave it as it is.

This rifle was pretty accurate to begin with so I'm hoping for the best.

HollowPoint

[Artful]

Just Wow - Very Impressive project :awesome:

[HollowPoint]

Thanks Artful:

I haven't even gotten to the gunsmithing part yet, but the farther along I get, the more confident I feel about achieving success with this project.

I might be able to set this jig up on the lathe this weekend. My long term work schedule is pretty much maxed out so the weekends will be about the only time I have to work on this dream.

At the end of each work day, I really don't feel like doing more work. I don't want this project to become like a second job. I want to keep it in the realm of a hobby project and I want to do this right the first time so I'm taking as much time as I need to, to get it done correctly.

I'm thinking/hoping it will be done by the end of January.

HollowPoint

[ratboy]

At the end of each work day, I really don't feel like doing more work. I don't want this project to become like a second job. I want to keep it in the realm of a hobby project and I want to do this right the first time so I'm taking as much time as I need to, to get it done correctly.

HollowPoint

i am very familiar with this. just tinker and it will be done before you know it.
looks super so far. i have no doubt this will end with a rifle many will envy.

[HollowPoint]

I was thinking the other night, "If I had all the tools and all the metal-stock and the barrel-blank ready to go and sitting on my work bench; and I didn't have to work for a living, this project would take me about a week to do." If I were to do another identical project after learning off of this one, I might be able to shave a day or two off of that time."

But alas; I still have to work for a living. Such is life for me now.

HollowPoint

[Wolfer]

Work really cuts into my hunting, tinkering time. I know there are people out there that make a living without working but I can't seem to do it.

[ratboy]

I was thinking the other night, "If I had all the tools and all the metal-stock and the barrel-blank ready to go and sitting on my work bench; and I didn't have to work for a living, this project would take me about a week to do." If I were to do another identical project after learning off of this one, I might be able to shave a day or two off of that time."
HollowPoint

the conundrum. if you did just that then it would become work and you would want to go do something else.
i have several project that i just cant wait until i get some time to work on them until i have some time then i want to do other things then i run out of time and wonder why i didnt get anything done.
it is the circle of life. maybe. im still not sure. the retired folks i know never have any time.

[HollowPoint]

Work really cuts into my hunting, tinkering time. I know there are people out there that make a living without working but I can't seem to do it.

Yea; I know what you mean. My next door neighbors never work. They have no visible means of income and yet, just about every weekend they can come up with enough money to buy enough booze to get drunk on.

If I were ever to retire and I had no hobbies, I think I'd go crazy; and drive everyone around me crazy as well.

On a project related bright note:

The metric thread-pitch-gauges I ordered last week showed up this morning. Anyone care to guess what the thread pitch is on a K31 Schmidt Ruben 7.5x55 rifle???? This information is "Holy-Grail" stuff. Before starting this project I scoured the internet in search of that very info with no luck in finding it. I even joined various forums that I wouldn't normally join just so I could ask that questions to those that one would think would possess that bit of knowledge.

The strange thing about alot of the "Experts" on the K31 is that they either don't want to share their knowledge or their just pretending to be knowledgable in order to impress others. Frankly, I don't think there is any such thing as an expert on the K31; I mean a hands-on expert. (other than the Swiss guys who designed and made them) Most are just book-learned-experts; or, experts by literary-osmosis.

The answer, according to my new metric thread pitch gauge is, 2.0mm per-whatever. I'm sitting here ragging on the so called, "Experts" and I have the exact answer but I don't even know how to write it down correctly. I have an excuse though. I'm bonafide ignorant about the K31 with just a pinch of knowledge.

I'm going to have to read my lathe's users manual all over again in order to swap out the correct gears for cutting metric threads now. Oh well; it was bound to happen sooner or later.

HollowPoint

[HollowPoint]

I took alot of pics and got as far as setting up my lathe for cutting the metric receiver-threads I'll have to square up. Setting up was the easy part; actually chasing and cutting the threads will be kind of tricky for me, especially since I've never cut metric-inside threads before. I've chased imperial threads before but they were outside threads.

I did run into some problems with my Receiver-Truing-Jig. Well, not with the jig itself but with the brass caps I was using on the ends of my Jacking-Bolts. (some call them spider bolts, some call them adjustment bolts) As I was truing up the face of the receiver, I noticed what looked like a barely perceptible wobble. It turned out that my Jacking-Bolts weren't bottoming out within those trimmed down brass 44 magnum shell casings and as I applied the slightest pressure with my cutting tool the receiver ever so slowly vibrated out of alignment. It's a good thing I caught it in time. It would have sucked if I'd screwed up my receiver without realizing it.

Initially, I must have spent two hours working to bring that receiver into alignment. Then after it vibrated out of alignment I had to run down to the hardware store to buy some brass screws that I could use as my end-caps instead of those brass shell casings. I drilled holes into the ends of my existing Jacking-Bolts and press-fit the brass screws into them. The heads of those brass screws gave me a much more solid hold on my receiver.

After measuring the runout on the receiver face, I found it to be .003" out of square with the axis of the receiver bore. Subsequent measurements of the other interior surfaces, including the threads showed a similar discrepancy in measurement to the squareness of the receiver's center line. I was hoping I didn't have to mess with this part of the receiver. This rifle was pretty darn accurate to begin with. It was surprising to find that it was out of square by three-thousands of an inch; although that's not really that much when you consider they were built for the most part on manual machinery.

If I get a chance tomorrow I'll cut those threads. If I get the time I'll also edit those photos and post them so you can see what I've attempted to describe. Some of those photos were taken before I replaced those brass ends on my Jacking-Bolts. I mention this so that I don't come off like I'm telling tall tails about the obstacles I've run into thus far.

HollowPoint

[HollowPoint]

I've superimposed text onto the images so they make a little more sense.

[HollowPoint]

Well, I got all the receiver work done. With any luck I'll be ordering my new barrel this Friday. Because of the diameter of the threaded tenon of the factory K31 barrel, the barrel I'll be ordering has to be "Special Ordered". The "Special" being a slightly larger diameter barrel blank than the typical 1.220" diameter barrel blanks sold by Shilen barrels. It takes four to six weeks for delivery of such a barrel.

Even this slightly larger diameter barrel is still not big enough around to turn the tenon with a shoulder on it like the factory barrel. That's OK though; I never intended to redo the barrel in its factory-shoulder configuration. I'll be making my new barrel using the Savage-Barrel-Nut method. I've used this method before and it made head spacing a whole lot easier for me. Although, with the K31's tenon configuration it really won't help with the head-spacing but, I believe it will still help simplify this project some what. The only draw-back (if it can be called a draw-back) is that I have to make a specialty Barrel-Nut. That's OK too because they're not that hard to make.

I believe there are a couple of other barrel makers who offer even larger diameter barrel blanks that would be ideal if I were re-barreling using the factory configuration but, this project is budget-driven and those other barrel maker's barrels are a whole lot more expensive. As it is, just the Shilen barrel alone costs more than what I paid for my K31.

Before truing-up my receiver, trying to screw the original barrel into the receiver was extremely difficult. It couldn't be done by hand. Now that I've trued-up the threads and the major interior flat at the front-most part of the receiver I can just about screw in the original barrel all the way by hand. Only the last quarter-inch or so requires a more forceful grip to do so. I believe it's because there is also two additional flat surfaces just ahead of the receiver lugs that I didn't true up.

I didn't want to take the chance of damaging or accidentally altering the lugs. Besides, the two small sections of interior flats just ahead of the receiver lugs shouldn't induce enough sideways pressure to take my new barrel off of the centerline of the axis of the receiver. It's the receiver threads and the major flat area visible in the images above that will be holding my new barrel on center.

HollowPoint

[IllinoisCoyoteHunter]

Looks great! I just finished my action truing/ chambering fixture with the intentions of doing some similar projects here at home. Where did you get your receiver bushings? Looking for a place to buy them where they don't charge an arm and a leg. Making them wouldn't be terribly difficult, but would like to have them perfect...and hardened (and I don't have a tool post grinder). Thanks!

[HollowPoint]

Sticker-Shock!

I was on the phone with Shilen barrels today to get my new "Special-Order" barrel ordered up. Everything was going well until the gal on the other end of the line told me that this "Special-Order" barrel could only be had in stainless steel; and because it was stainless steel the total price when shipping was tacked on would be well over a hundred dollars more than originally budgeted for.

Plan-B:

All is not lost. I've had a "Plan-B" and a "Plan-C" in place just in case I ran into problems like this. "Plan-B" entails the making of a 4041-alloy threaded barrel-stub to match the factory K31 barrel-tenon so that I don't have to cannibalize my existing factory barrel. Into that barrel-stub will be screwed my new smaller diameter and much less expensive Chrome-Moly barrel blank. (which has now been ordered)

What is "Plan-C" then?

"Plan-C" would have been my last-ditch effort to salvage this project. It would have meant chopping off the existing tenon from the factory barrel and converting the existing barrel-tenon into my threaded barrel-stub. For me, this would have been the near equivalent of a failure with this project. Like I mentioned before; I didn't want to have to use my existing barrel as a means to completing this project. I wanted to keep that factory barrel unaltered just in case I ever wanted to re-install it or sell it off to recoup some of the expense of this project.

I ordered a short length of 1-1/2" diameter 4140 alloy steel off of the fleebay auction site. The frustrating thing is that all this took place the day after I had started making the Barrel-Nut I'd be using for my original re-barreling plan. It was coming along nicely; with carefully done class-3 threads and the whole nine yards. Now I'll have to make another one cause the thread pitch will be slightly different; not quite so course as the factory 2.0mm thread pitch.

Oh well; live and learn. This is how you get smarter the hard way. I'll post a picture of my partially completed barrel-nut just for laughs. In spite of this small setback, things are actually moving along faster than I'd expected but not so fast as to be overwhelmed by it all.

This gives me the time to come up with the money to buy the 6.5 mm range rod and the chamber reamer I'll be needing. I'll most likely sell those off once I'm done with them just to recoup more of the cash out-lay for this project.

Oh, and here's an off-the-wall idea; Is there anyone following this thread that has a 6.5 mm Range-Rod that would be willing to loan it to me if I offered to pay the insured shipping to and from? I have a .224 and a 30 caliber Range-Rod. If you happen to be doing a barrel project that requires one of these sizes in order to index your barrels, perhaps we can do a temporary equal-loan-swap; return them when we're done kind of thing. I'm still going through with this project wether or not anyone is interested in this possibility. I thought I'd just throw it out there.

I'll be back.

HollowPoint

[HollowPoint]

Looks great! I just finished my action truing/ chambering fixture with the intentions of doing some similar projects here at home. Where did you get your receiver bushings? Looking for a place to buy them where they don't charge an arm and a leg. Making them wouldn't be terribly difficult, but would like to have them perfect...and hardened (and I don't have a tool post grinder). Thanks!


Thanks CoyoteHunter:

I made the receiver bushings myself. Although they aren't professionally made, I've found that using Drill-Rod a half-inch or larger in diameter is generally straight enough to use as a truing guide. The tapered ends were turned on my lathe. As short as they are I'm more than sure they're just as true as the Drill-Rod I'm using. According to my dial indicators, my chinese metal lathe is more accurate than I am as a machinist.

The truth is, I'm just to cheap to buy them already made up. And when you consider that this is a one-off project, chances are low that I'd ever use them again. I haven't heard of alot of DIY'ers that work on K31's so it would be hard to recoup the money one would pay for a specially made store-bought set of K31 bushings.

Thanks for you input.

HollowPoint

[HollowPoint]

Here's a couple of pics of the Barrel-Nut I wasted some time on. It turns out I won't be using it but, I'm hanging onto it just incase.

Not pictured here is the additional spacer I had yet to make. The "Spacer" would have been sandwiched in between the Barrel-Nut and front face of the receiver. It would have given me an area of metal I could drill and tap to have used as an anchor point for the front end of my scope rail.

My "Plan-B" Barrel-Stub-Tenon will now be acting as the anchor point for my scope mount. It too will be drilled and tapped in order to secure my scope rail. I'll have to wait till I get that far along for me to show you what I'm talking about. Right now it probably doesn't make any sense to you.

I'll be back when I get farther along.

HollowPoint

[N4AUD]

This is a very interesting threat to me. I'm a big fan of the K31 and have killed several deer with one. I understand MOST of what you are doing, but not all, since I've never done it myself. I'll be following with interest.

[Frank46]

Very interesting thread and machining along with great photo's. Will be following this one. Frank

[HollowPoint]

Thanks guys: I'm hoping that the 4140 metal I ordered shows up before mid-week next week. I may have about a day and a half of free time to at least get started on the Threaded-Tenon-Stub I was alluding to in my previous posts.

Things are looking good right now but I don't want to get ahead of myself.

HollowPoint

[Artful]

Out of curiosity what was the quoted price on the SS barrel blank from Shilen?

[HollowPoint]

It was just over three hundred dollars according to the gal on the phone. I could have special ordered this same barrel through midwayusa for a slight discount but not enough to make any difference as far as my budget for this project.

The standard No.4 profile chrome moly 1 in 8 twist barrel runs around $175.00 if you get it during one of their free-shipping campaigns. Even with the additional purchase of that short length of 4140 round stock the total price for the barrel will be below a couple of hundred bucks.

HollowPoint

[HollowPoint]

I had a light day of work today so I went ahead and Powder Coated all the small parts that would have otherwise had to have been re-blued. I decided to go with a flat-black finish instead of re-bluing. It didn't take to long and everything turned out looking pretty good. While I was at it I also sanded down the wooden stock and wiped it with a lighter stain than it formerly had. I still have to apply some clear over the top of it. I just want to wait till it's had a chance for the stain to dry completely. I'm wondering if I can forego the clear coat and just apply some paste wax on the finish. I'm not all that knowledgeable in the realm of wood finishes so I'll have to do some research before I proceed.

I know I'm getting ahead of myself but free time doesn't come as easily for me as it once did; and since all I was doing was waiting for my recently ordered barrel and metal stock to arrive, I thought I'd use that time to do the stuff that I would have had to do eventually anyway.

I haven't decided how I'll go about coating the barrel itself. My little powder-coating/toaster-oven isn't nearly big enough to fit my barrel into for curing a layer of powder coat. I'll think of something. I may just cold-blue it and then spray a couple layers of flat black paint over that.

HollowPoint

[HollowPoint]

My new barrel and my chunk of 4140 metal stock showed up late yesterday afternoon. I was able to set it up on the lathe and at least start shaping the outside diameters and threads. I got a real nice-snug slop-free fit on the threads and interior flats surfaces. I turned the outside shape slightly different than the factory tenon. That "difference" was in the form of eliminating the thread-relief-cuts so as to increase the support-strength of the overall length of this part.

I got as far as finishing up the outside geometry and threads of my threaded-barrel-stub. Because of this "Plan-B" method of installation, I've been pondering the optimum thread pitch I should use for mating the barrel tenon itself to the inside threads of the threaded-barrel-stub.

I don't want to use a thread pitch as course as the metric 2.0mm threads that the factory K31 barrel was screwed into the receiver with. That would give me too-course of a thread setup above and below and possibly compromise the strength of the threaded-barrel-stub; not to mention it would make the walls of my chamber just a tad thinner than I'd like. After checking around the internet for the various thread pitches used in other rifles with calibers equal to or greater than the 6.5x55 Swede, I've decided to use a one-in-14 thread pitch for mating my new barrel to the threaded-barrel-stub.

I went back and forth between a 1 in 16 and a 1 in 14 thread pitch for the same reason. The factory tenon only has about an inch of total threads from front to back on the existing tenon. I can see why they used such a course thread pitch. It most likely gave a more secure hold than a one inch length of finer threads.

With this threaded-barrel-stub setup I have about a 2-1/4" length of overall threads so going with a little finer thread pitch should still secure my new barrel without issue; and, as I've already mentioned, it will allow me to keep the walls of my barrel chamber and the walls of the threaded-barrel-stub as thick as possible; given this setup.

I know it's hard to visualize with just the written word being used to paint a mental picture. I'm afraid that what I'm writing won't make any sense until I post some of the pictures I've taken. I'm hoping to have this threaded-barrel-stub done tomorrow. I still have to bore out the "Minor-Diameter" hole that I'll be cutting my inside diameter threads into. After that I can remove the newly turned part from my metal stock and proceed to index, mark and then cut the angled extraction-cam and extraction-notch.

I'll be back after I've finished this part and edited some of the photos I've taken.
HollowPoint

[Artful]

I haven't decided how I'll go about coating the barrel itself. My little powder-coating/toaster-oven isn't nearly big enough to fit my barrel into for curing a layer of powder coat. I'll think of something. I may just cold-blue it and then spray a couple layers of flat black paint over that.

HollowPoint

I read of some using a section of 36" long stainless steel double wall fireplace chimney pipe with a hot plate in the bottom,
a lid with a damper on top, and a BBQ grill thermometer to watch the temp.
Loose brick base for the hot plate to set in, and the pipe to set on top of.

Another was the aluminized insulated board formed into a long box which opened from the top and he mounted heat lamps about every foot or so and controlled it with a dimmer switch and had two probe digital thermometers with alarms to monitor the contents.

Here's a quote from Mac's Shooting Irons http://www.shootiniron.com

Any metal cabinet will work as long as you insulate it. Drywall works fairly well for that. You can also use cheap tile layed in the bottom as a heat refelctor. I built a "hot box" for heating the parts getting Guncoated using ceramic tile in the bottom as heat reflector for the heating coils and insulated it with dry wall.

I've been using that thing for years and it works very well. The one thing that I would add: If you do a lot of curing, don't waste time with mechanical thermostats. Spend the few extra dollars and get an electronic heat controller. You can get them on Ebay for less than $20. (Watlow, Omega, etc)

Those will ramp the heat up in stages instead of just "flame on".

Regarding fans: Excellent suggestion! My big curing oven has a metal bladed fan that extends thru the top on a long shaft. It blows the air around inside the oven like a whirlwind and keeps the temp even throughout. Keep yer powder dry, Mac.

Lots of You Tube plans to make a curing oven

https://www.youtube.com/watch?v=NeRSp-YBIpE

https://www.youtube.com/watch?v=81t1aYxJer0

Other links

http://www.stickbow.com/features/bowbuilding/heatbox.CFM

http://www272.pair.com/stevewag/heater/heater1.html

[Cap'n Morgan]

Since you'll be doing all threading on a lathe, you could go for any thread profile you want. Instead of full profile threads you could use a thread with flat root and crest, thereby making the thread profile lower for the same pitch. The "pointy" parts of a thread adds very little to the actually strength and 0.02-0.03" is plenty of height for a 1 in 14 thread. Also you could change the compounded angle profil from 55 or 60 degree to 30 as this (theoretical) would lessen the radial outward pressure on the barrel stub.

[HollowPoint]

I read of some using a section of 36" long stainless steel double wall fireplace chimney pipe with a hot plate in the bottom,
a lid with a damper on top, and a BBQ grill thermometer to watch the temp.
Loose brick base for the hot plate to set in, and the pipe to set on top of.

Another was the aluminized insulated board formed into a long box which opened from the top and he mounted heat lamps about every foot or so and controlled it with a dimmer switch and had two probe digital thermometers with alarms to monitor the contents.

Here's a quote from Mac's Shooting Irons http://www.shootiniron.com


Lots of You Tube plans to make a curing oven

https://www.youtube.com/watch?v=NeRSp-YBIpE

https://www.youtube.com/watch?v=81t1aYxJer0

Other links

http://www.stickbow.com/features/bowbuilding/heatbox.CFM

http://www272.pair.com/stevewag/heater/heater1.html


I was mulling this over last night and I thought maybe I could insulate the door area of my tiny little toaster oven so as to powder coat the rear half of my barrel -stuck into my oven at an angle from corner to corner- then turn it around and do the other half.

Of course, this would still leave a short section in the middle of my barrel's overall length that wasn't powder coated. That center section is hidden underneath the forestock so from an asthetic point of view, it may not be an issue. That center section can just be cold blued and painted.

This is a budget project. Nearly everything I've done to this rifle thus far has been by using stuff I already had on hand; either in my junk drawers or out back in my junk pile. The stain for the stock, the urethane for the finish, the cold blue; should I need to use it, the flat black powder coat; all of that stuff I just happened to have on hand already.

The only thing I've had to buy or have already bought are the barrel, the reamer, and the range rod. The 4140 metal stock I bought using the spending money I had in my paypal account so I really don't count that as an expense; per se.

I'm trying to avoid spending any more money than I have to on this project. I have a friend/customer who has a powder coating oven large enough to do a 26" barrel if I set it in there from corner to corner. Since both ends of my barrel will be threaded, I might be able to just lean it inside the oven. That's if he's open to loaning it to me.

HollowPoint

[HollowPoint]

Since you'll be doing all threading on a lathe, you could go for any thread profile you want. Instead of full profile threads you could use a thread with flat root and crest, thereby making the thread profile lower for the same pitch. The "pointy" parts of a thread adds very little to the actually strength and 0.02-0.03" is plenty of height for a 1 in 14 thread. Also you could change the compounded angle profil from 55 or 60 degree to 30 as this (theoretical) would lessen the radial outward pressure on the barrel stub.

I get the just of what you're saying; and it makes sense. Actually, I had already planned on using 1 in 14 pitch thread without going to their full profile; for all the reasons you've just stated. The thing is, when I cut these threads as "Class-3A" and "Class-3B" threads, it makes an already tricky procedure even trickier for me. I mentioned before, "I'm neither a gunsmith nor a machinist." Cutting full profile "Class-3" threads is tricky enough for me as it is. Cutting these same "Class-3" threads and intentionally giving them flat tops and bottoms adds a little more complexity for me.

I think that as long as the threads themselves mesh perfectly together as should be the case with "Class-3" threads, the thickness of the chamber walls and the thickness of the threaded-barrel-stub walls (within reason) shouldn't be a problem. If the threads fit snuggly together, there will be no microscopic gaps large enough for the metal to creep into and out of shape under the pressure and heat that's experienced with repeated discharging of cartridges; I hope.

If I start to get the sense that my deliberately flattened thread tops and bottoms don't look like I'm hoping they will, I can just keep cutting them to their full profile and go with that. No harm, no foul.

I found the following website that has been a big help with calculating the nuances of all the various thread pitches. It's alot cheaper than buying a Machinist Handbook. I just wish I could find a similar website that would help with metric threads.

http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx

HollowPoint

[Cap'n Morgan]

I found the following website that has been a big help with calculating the nuances of all the various thread pitches. It's alot cheaper than buying a Machinist Handbook. I just wish I could find a similar website that would help with metric threads.

http://theoreticalmachinist.com/Thre...dImperial.aspx (http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx)

You can try this one. It's in German, but Google translate is your friend. Unfortunately it doesn't allow for thread gauge wire calculation:

http://www.iso-gewinde.at/

Or you could try the program "threadTech" It's a great program as it will allow for any thread gauge wire size you may want, but it's probably overkill unless you make threads for a living. You can download a 30 days trail version here:

http://www.threadcheck.com/content/software_download.asp


Metric thread tolerances are based on the ISO system and can be a bit daunting at first look, but it makes good sense once you get the hang of it.

http://www.boltscience.com/pages/screw8.htm

[HollowPoint]

Here are a few more pics with some explanatory text superimposed onto them. Hopefully they'll clarify some of what I was attempting to describe in my previous post.

I still have to mark and cut the Extraction-Notch as well as the Angled-Extraction-Cam and a small flat on the bottom of my threaded stub. I'll post pics of that after I get those operations done.

HollowPoint

[Plate plinker]

I don't know much at all about this process but you seem to getting on well for a home gunsmith.:drinks:

[HollowPoint]

I assure you, it only looks that way. Since I've never worked on a K31 before there still exists a certain sense of trepidation about it. In the back of my mind are all of those comments I came across during my research into this K31 re-barreling project. ("The Angles Are To Complex, It's Not Worth The Trouble, There's only a few guys in the world that know how to work on these rifles, It's going to be real expensive." And of course, there's the replies of the purists; "Why Would You Want To Bubba Such A Fine Rifle?")

When you add all of those negatives to my own sense of trepidation; Like, Did I cut the threads with enough precision? Are my measurements tight enough to ensure safety and reliability? Is there anything I've forgotten to do or to check? After all of this work and money spent, will it be blown to smithereans when I go to proof test it?

On the other hand, if I end up with the kind of rifle I've dreamed of building, I'm afraid that I'm going to be a Cocky-SOB for a short period of time shortly there after but, I'll get over that soon enough. From then on, any time I come across a Dream-Killing remark about a K31 re-barreling project, I'll be able to hold my own against the self-appointed-experts. Having successfully completed this K31 re-barreling/re-chambering project, any similar projects on just about any other type of bolt action rifle will seem immensely doable by comparison.

HollowPoint

[ratboy]

When you add all of those negatives to my own sense of trepidation; Like, Did I cut the threads with enough precision? Are my measurements tight enough to ensure safety and reliability? Is there anything I've forgotten to do or to check? After all of this work and money spent, will it be blown to smithereans when I go to proof test it?
HollowPoint

imagine what the guys who built the apollo rocket were thinking when they saw it headed to the launch pad.
:shock:
from what ive seen so far, i expect a positive outcome. problem is once this works, you will start coming up with other "projects"

[Artful]

I was mulling this over last night and I thought maybe I could insulate the door area of my tiny little toaster oven so as to powder coat the rear half of my barrel -stuck into my oven at an angle from corner to corner- then turn it around and do the other half.

Of course, this would still leave a short section in the middle of my barrel's overall length that wasn't powder coated. That center section is hidden underneath the forestock so from an asthetic point of view, it may not be an issue. That center section can just be cold blued and painted.

This is a budget project. Nearly everything I've done to this rifle thus far has been by using stuff I already had on hand; either in my junk drawers or out back in my junk pile. The stain for the stock, the urethane for the finish, the cold blue; should I need to use it, the flat black powder coat; all of that stuff I just happened to have on hand already.

I'm trying to avoid spending any more money than I have to on this project. I have a friend/customer who has a powder coating oven large enough to do a 26" barrel if I set it in there from corner to corner. Since both ends of my barrel will be threaded, I might be able to just lean it inside the oven. That's if he's open to loaning it to me.

HollowPoint

If he doesn't what else you got around - heck two layers of drywall is a firewall rate for 1 hour against open flame - build your bake box/flue out of that - do it horizontally and put the toaster oven on one end with door removed and a flue with a fan to move the hot air down the box - on the other end put a flapper that's controllable - steal the thermometer from your BBQ to make sure the temps up to spec's. This ain't rocket science.

Heat Source + container to hold the heat and the part + way to measure the temp and control the temp - That's it

[HollowPoint]

imagine what the guys who built the apollo rocket were thinking when they saw it headed to the launch pad.
:shock:
from what ive seen so far, i expect a positive outcome. problem is once this works, you will start coming up with other "projects"

"Once It Works"

Yea; I've found that like other projects I've done, no sooner do I get near the end of my project that I figure out ways I could have done it better or easier. From that learning process comes those "Other Project" you elude to. I agree with you.

In the back of my mind I have thoughts of re-barreling my Lee Enfield No.4 yet again. This time around I'd true-up that receiver as well and go with a 1 in 14 twist barrel instead of the 1 in 10 that I used before. Since it's my dedicated lead plinker, a slower twist would be ideal for me.

On a subject related note: I got the Threaded-Barrel-Stub done yesterday. I thought I had every measurement checked and re-checked for a perfect fit. I torked it into place with high hopes of the action working perfectly the first time with no do-overs. NOT. With the Threaded-Barrel-Stub in place, I couldn't get the bolt to go into battery. It would stop short of going all the way in.

I thought to myself, WhatTheHell! All my Barrel-Stub measurements were right on the money. Why is this not working? Then I remembered that when I squared up the face of my receiver I had taken off about three and a half thousands of metal. This meant that when I torked down my Threaded-Barrel-Stub into the receiver, it was seated a good five-thousands or so deeper than it was intended. Hence the failure to go into battery. In my hurry to finish the Threaded-Barrel-Stub, I failed to take that into account. It's an easy but annoying fix. Better to have three-and-a-half-thousands of metal to be removed than to come up short and have to start from scratch. It was then that I ran out of free time.

I have some more free time near the end of the week. I can get those bugs ironed out then and move on to ordering my Range-Rod for the next step in this project. I'll be setting my new barrel up on the lathe for doing both the indexing and the threading of the tenon and muzzle.

HollowPoint

[HollowPoint]

I finally got it done and re-tested. My bolt now goes into battery as it should with just a hint of contact between the right-side Bolt-Lug and the Angled-Extraction-Cam on the face of the Threaded-Stub.

I'll have to wait till I have the new barrel installed in order to fully test the actual extraction of the empty shells. I'm confident it will work though.

Although going to "Plan-B" has added some extra work to the front end of this project, I do think that in the long run it will save me some time when it comes to head-spacing. In theory, I should now be able to just cut my chamber so that my 6.5x55 brass sits at that same depth as an empty 7.5x55 casing fits into the factory barrel chamber. From there it's just a matter of removing the extraction claw from the bolt and screwing the new barrel down till it touches the bolt-face. (with a go-gauge in place of course) Then I can tork down the Barrel-Nut and proof-test it. Lets hope it works out so easily.

Here are a few of the pics of what I went through in order to get it to work. I hope they make sense to you all. If not, you're allowed to ask questions.

HollowPoint

[Cap'n Morgan]

That's neat! The idea of using a template and file never crossed my mind. Too many years of CNC I guess...

Is the original cam hardened in any way?

[McFred]

Thank you HollowPoint for this thread. I remember years ago when I stumbled onto the K31 straight pull milsurp rifle. It piqued my curiosity but I never followed up on it. Now I'm shopping for one I can reverse-ably sporterize for a 284Win scout rifle I can take to the local rifle matches to badger the local tacticool and F-class guys. (I'm heavily invested in high BC 7mm components). :D

Along those lines what is the max cartridge overall length the magazine supports (if I may ask)?

Really looking forward to the range report!

[HollowPoint]

That's neat! The idea of using a template and file never crossed my mind. Too many years of CNC I guess...

Is the original cam hardened in any way?

I don't know if it's hardened or not. When I was filing my templates; as I held them pressed against the factory tenon, the file had no problem scoring the finish of the factory Angled-Extraction-Cam so I'm thinking; if it was originally hardened the repeated extreme heating and then cooling of the chamber area of the factory barrel had long since annealed to its original neutral state of hardness. There's no way I can prove it though.

I think that at a minimum, the level of hardness of the factory tenon area as it exists right now and the hardness of the 4140 alloy metal stock I used to make the Threaded-Barrel-Stub are pretty close to the same; with the 4140 being the newer un-fatigued metal.

I'll have to measure the length of the inside of my K31's magazine in order to answer the "Max overall length of the cartridge" question. Right now I have to go to work. I'll post an answer this afternoon.

HollowPoint

[Cap'n Morgan]

Hollowpoint.

The reason I'm asking is that back in the day actions and bolts were often hardened to different hardness in different areas. A cam, like the one on your barrel, could have been flame hardened for wear resistance without the process interfering with the rest of the chamber. Anyway, a smidgen of molycote based grease should prevent any galling.

[HollowPoint]

I might go ahead and flame-harden that small section of the Threaded-Barrel-Stub; at least the very face of it. I'll just have to wait and see. I don't want to go from perfectly-fine as it is, to brittle and prone to breaking off down the road.

I got a chance to measure the inside front-to-back length of my K31 magazine. It measures 3.130" or there abouts so I guess this would be the max length we could make our reloads.

HollowPoint

[HollowPoint]

My 6.5 mm Range Rod has now been ordered. While I'm waiting for it to arrive, if I get enough free time to do so I'll try to get ahead of this project by roughing out the inletting in the stock so that there will be less of it to do when the time comes. I can also go ahead and Powder Coat the Threaded-Barrel-Stub and Scope Mount while I'm waiting.

Because of the added shape of the Barrel-Nut and the Threaded-Barrel-Stub there's no way the action will fit back into the stock as it is. Also; I'm going to have to make another Globe-Front-Sight to fit the slightly larger muzzle diameter of my new barrel. Besides the different diameter at the muzzle, the Globe-Front-Sight I installed back when I first got this rifle has broken on the underside where my securing screws hold it onto the barrel.

Ordering the chamber reamer will be last on my list of expenses for this project. I'm still holding out hope that I can find a 6.5x55 Swedish Mauser reamer in excellent shape for a whole lot less than buying one new. I mentioned this before. If I end up buying a new one, I'll probably sell it as soon as I'm done with it. I'm thinking I can sell it and end up having paid about the same as if I'd rented one instead. The only difference will be that I can keep it as long as I needed to while I wait for some more free time to become available without having to pay the extra money for keeping it longer than three days or so; same with the Range-Rod.

This is easier said than done cause I'm a sort of a Pack-Rat when it comes to tooling of any kind. Even if I never use them again, it's like selling off your kids or renting out your wife. If I get rid of them, I know that there will come a time when I'll kick myself for getting rid of them.

I almost forgot; I also have to drill and tap the two holes in the shoulder of my Threaded-Barrel-Stub so that I can secure the front of my Scope-Mount at that location.

HollowPoint

[HollowPoint]

On Saturday morning I started work on forming the outside dimensions of my Barrel-Nut. For those of you who own a K31, you'll note that the top section of the fore-stock has about a half-inch wide piece of metal trim slip-fit over the back end of it.

This "Metal-Trim" has a claw of about an eight inch or so protruding from the rear of it. This little claw slips into an undercut in the factory rear sight to secure the rear section of the upper fore-stock in place.

Because I will no longer have the factory rear sight to use as the anchor point for the upper fore-stock, I've had to design my Barrel-Nut so that it acts not only as a Barrel-Nut but also as my anchor point for the upper fore-stock. I've shaped it so that it curves/tapers down from the shape of a conventional Barrel-Nut to the shape of a curved/tapering barrel.

The overall length is about an eight-inch less than three inches. This is the amount of space that is left open when measuring from the face of my Threaded-Barrel-Stub (when screwed into place) to the back end of the upper fore-stock.

I still have to smooth out the curve of the outside surface of this newly made part. Also, once I finish the outside I'll have to wait till I've actually threaded the chamber end of my barrel before I thread the inside of this new Barrel-Nut. This is because I want to be able to use the threaded barrel itself to check the fit of the inside threads I'll be cutting into my Barrel-Nut. It's time consuming this way but, at my lower level of inexperience it's the best way I've found to make sure I get slop-free thread engagement.

The Barrel-Nut itself will only have an inch and a quarter of thread engagement. The remainder of the three inch length will be bored so as to slip over the outside diameter of the barrel itself. An additional shallow depth of counter-bore will be cut into the inside front end of the Barrel-Nut to act as the anchor point where the upper fore-stock claw hooks into.

This is another one of those instances where trying to describe something simple with the written word makes it sound a whole lot more complicated than it really is. I'll take some more pics and post them as well so that my ramblings make a little more sense.

I'll be back.

HollowPoint

[Artful]

I got a chance to measure the inside front-to-back length of my K31 magazine. It measures 3.130" or there abouts so I guess this would be the max length we could make our reloads.

HollowPoint

Looks like the magazine will be just a tad short
http://www.6mmbr.citymaker.com/i/Tech%20Diagrams/65x55.png

http://www.mynetimages.com/9374e37416.jpg
http://precisionrifleblog.com/wp-content/uploads/2014/10/best-long-range-cartridges-with-diagrams.png

[HollowPoint]

"Looks Like The Magazine Will Be Just A Tad Short."

I'm pretty sure it all depends on the actual bullets being used. Because there are so many projectiles to choose from, that information isn't specified in this type of general information; or if it is, it may not necessarily be the bullet of choice of the guy doing the reloading. Even if it's the longest bullet available, it can still be made to work. It just won't be as long as the literature states, that's all. A competent reloader can work around it and still achieve what they're seeking as far as performance. At least that's my take on the caliber I've chosen to go with.

Here are a couple more pics that should explain most of what I attempted to describe in my previous post.

The outside of my Barrel-Nut has now been shaped to the way I want it. The stock has been inletted to accommodate this new part. The only thing left to do is thread the inside to match the threads I'll be cutting into the barrel blank.

At this point I've gone as far as I can. Until I receive the Range-Rod I ordered all I can do is make up the CAD drawing for my new Globe-Front-Sight and come up with the G-Code to cut some flutes into the gripping section of my Barrel-Nut.

I hope it all makes a little more sense now.

HollowPoint

[Cap'n Morgan]

I think the 3.149" OAL (80mm) is the absolute MAX for the Swede with the original 156 grains bullet. Most of the recipes I've seen is 3.1 or shorter..

[HollowPoint]

I think the 3.149" OAL (80mm) is the absolute MAX for the Swede with the original 156 grains bullet. Most of the recipes I've seen is 3.1 or shorter..


Yea: I have a copy of an old Hodgdon reloading book in which every bullet weight is listed at less than 3.149" overall length. Even the long 160 grain round nose is listed at three-inches even. The longest OAL loading is listed at 3.050" for the 142 grain Sierra Hollow Pointed Boat Tail.

The cartridge over all length wasn't really a factor in my choice of cartridges. I just wanted something with a little less recoil; something a little different from the norm in a K31.

The information posted by Artful is very valid and a good starting place when dealing with the 6.5x55 Swede but, it's not written in stone. Even if I wanted to load to the lengths listed in those diagrams, I still could; provided the chamber throat was cut to do so. It would just mean I'd have to load them into the chamber by hand and not through the magazine.

HollowPoint

[N4AUD]

"Looks Like The Magazine Will Be Just A Tad Short."

I'm pretty sure it all depends on the actual bullets being used. Because there are so many projectiles to choose from, that information isn't specified in this type of general information; or if it is, it may not necessarily be the bullet of choice of the guy doing the reloading. Even if it's the longest bullet available, it can still be made to work. It just won't be as long as the literature states, that's all. A competent reloader can work around it and still achieve what they're seeking as far as performance. At least that's my take on the caliber I've chosen to go with.

Here are a couple more pics that should explain most of what I attempted to describe in my previous post.

The outside of my Barrel-Nut has now been shaped to the way I want it. The stock has been inletted to accommodate this new part. The only thing left to do is thread the inside to match the threads I'll be cutting into the barrel blank.

At this point I've gone as far as I can. Until I receive the Range-Rod I ordered all I can do is make up the CAD drawing for my new Globe-Front-Sight and come up with the G-Code to cut some flutes into the gripping section of my Barrel-Nut.

I hope it all makes a little more sense now.

HollowPoint
Keep the pictures coming! I could picture in my mind what you were saying but those two images are really worth a thousand words! I don't see the OAL for the new cartridge as being a problem, any good reloader can get around it. Just loading for the K31 in the original cartridge requires some work in that respect due to the shape of the nose of the Swiss bullets. Through the years I've simply measured the length of factory ammo and loaded my handloads to the same length...until the K31. When I did that, the bullet would jam into lands. I think the first round I loaded actually had the bullet pulled when I was able to hammer the bolt handle back! But I learned from it, so it wasn't a loss in my book.

[Artful]

"Looks Like The Magazine Will Be Just A Tad Short."

I'm pretty sure it all depends on the actual bullets being used. Because there are so many projectiles to choose from, that information isn't specified in this type of general information; or if it is, it may not necessarily be the bullet of choice of the guy doing the reloading. Even if it's the longest bullet available, it can still be made to work. It just won't be as long as the literature states, that's all. A competent reloader can work around it and still achieve what they're seeking as far as performance. At least that's my take on the caliber I've chosen to go with.

Oh, granted but I always try to look at what factory ammo does it eat and what length do they use as MAX.

[HollowPoint]

I got a call from the guy whose car I was scheduled to work on this morning. It turns out he came down with the flu so he wasn't able to make his appointment.

What that means is, I got the next two days off. That also means that I might be able to finish up the Globe-Front-Sight I mentioned in my previous post. I was also going to try to finish up the fluting on the Barrel-Nut but it occurred to me that it might be better to wait until I've gotten a chance to thread my barrel and the inside of that Barrel-Nut first.

If I flute that Barrel-Nut now I run the chance of having the timing of the flutes off just far enough to cause one or two of those flutes to end up in an incorrect position. I want for the raised flat sections to fall even with the upper edges of my rifle stock so if I wait till I've threaded the barrel and Barrel-Nut I can screw them down hand-tight and mark my top dead center at that time.

With the top dead center determined, I can then set it into the 4th-Axis of my mill and the flutes should automatically fall into place. I'm not smart enough to time the threads themselves. It's easier for me to time the flutes.

Here's a couple of computer renderings of the parts I hope I end up with. Wish me luck.

HollowPoint

[HollowPoint]

I got an email this morning from PTG telling me that they'd just gotten around to shipping the Range-Rod I ordered a few days back. I decided to order directly from them because it was a few dollars cheaper than ordering from Midwayusa or any of the other online sellers.

I don't know if they always take their sweet time to ship stuff or it's a result of the holiday season. Oh Well; it gave me the chance to finish up my new Globe-Front-Sight. It's one less thing I have to do now.

I can't do anything more until I've threaded my barrel. Wouldn't you know it; on the rare occasion I get some free time, I'm having to wait on the tools to move forward. I guess I could use this time to rake the yard; or wash the truck or watch the Outdoor Channel.

Na.

Here's a couple of pics of the Globe-Front-Sight I just finished. I'll be back when I get farther along.

HollowPoint

[Frank46]

HP your old globe front sight looks like the one sarco sells. Made by Parker hale and came with a card of inserts made by Lee Shaver. Also came with a sight mounting block and two screws. The sight block was made for a round barrel. Frank

[HollowPoint]

I've only made four of these all together. Except for the one on the right that I broke when I over tightened the installation, the others were mounted on a lever action 44 mag, two Enfields and my air rifle. This just seems to be the easiest style to make.

I made the one I have on my Enfield now with windage adjustment on it. The others, like the one on my air rifle has windage adjustment on the Rear-Peep itself. On the broken one pictured above, I actually only made the bottom section. It was made with a dove-tail on top to accommodate a Globe-Front-Sight that came off of an old air gun I used to have.

I could never get used to the front sight inserts that, that particular type of Globe-Front-Sight used. I just couldn't get as precise of an aim with them so I started using fine-wire to form cross-hairs just like on a scope. The cross-hairs allow me to get a more precise aim at longer ranges where the old-style inserts would obscure or cover most or all of my intended target.

HollowPoint

[Frank46]

I've used a couple of different globe target sights and they have had different types of inserts. The Tiger eye I have uses clear plastic inserts with a beveled hole that in effect leave a shadow to help align the eye on the hole. Redfield used something similar but also used inserts with both horizontal and verticle pieces again for alignment. And as stated the Lee Shaver inserts are stamped in different configurations. I have an old Vaver front globe front sight that has the horizontal and vertical lines as part of the sight itself and comes with about 8 threaded cylinders with different apertures and you just change out by unscrewing them and screwing in the new one. When I had younger eyes it was easy to swap out the inserts on the tigereye sight. Now with older eyes I need as much light as I can get. Too small and cannot get good sight picture. Keep up your build and the excellent pics. Looking good so far. Frank

[fivefang]

it is a wonderful feeling to follow your instinct,I once made a "Reduced Rim 45/70 on a Steyr 95 streight pull,the action wrench I made works on LG.& SR Mau. typ:38 & 99 Ari.,SMLE ,Steyr 95,using spacers& Shims, I'm not a Gunsmith, just a Millwright who likes to play in the shop of my own

[HollowPoint]

Thanks for the encouragement guys:

Yesterday I was going crazy cause I had a full day of free time but no tools to carry on the work with. I've done just about everything I can for now.

I was laying in bed the other night mulling over the steps I'd be taking when I finally did the actual chambering on my new barrel blank. It occurred to me that I hadn't come up with a good way to hold my chamber reamer as I reamed out this new chamber. I was going to try to make a "Floating-Chamber-Reamer" holder but I had an epiphany as I lay there in bed.

I'm going to be using one of the tool-holders from my Tormach CNC mill. It's proprietary tooling that includes a holder that uses ER collets. The tail end of these holders fit nicely into the tail stock on my lathe. It doesn't have a tapered fit, it's just cylindrical but, it's just the right size to allow it to float from side-to-side and up-and-down about an eighth of an inch in all directions. I didn't want to just chuck the reamer up in my tail stock. I wanted the reamer to float. If I remember to do so, I'll take a picture of what I'm talking about. This method might come in handy for some of you other home gunsmiths.

About the only other thing I was going to play with on this project is the "Ejector." It's the little flat bar that raises up as the bolt is pulled back to kick the empties up and back over our shoulder. Because my scope sits on the center line of the bore directly over the ejection port, I have a Pivoting-Ejector integrated into my home made scope mount. This Pivoting-Ejector works reliably enough as it is but, it requires a brisk pull-back of the bolt to get the empties to really eject; as apposed to dribbling out the side.

On the shooting bench or even out in the field, I don't really mind my empties dribbling out the side of my receiver. It comes in kind of handy cause I dont' have to go searching for any of my empty brass. It's generally laying at my feet. I just have to bend over and pick it up. BUT, even getting my empty brass to dribble out the side requires a certain amount of speed when pulling the bolt back. If I miss that speed-window the empty will come part of the way out then roll back on top of the magazine.

I'm thinking that by fabricating a new "Ejector" and tweaking the front-to-back width of it I can get the empty brass to start pivoting upward just an instant sooner, which will give my "Pivoting Ejector" earlier contact with the brass. This earlier contact will be while the brass is in a position within it's ejection-cycle that it has more clearance on all sides to eject cleanly out the side rather than bouncing against the inside of the receiver at the base of the brass on its way out.

This description is yet another one of those attempts at describing something simple with the written word and having it come out sounding far more complicated than it really is. For those of you who own a K31, next time you're playing with you rifle, take a look at how the ejector works in your gun. You'll be able to tell what I was talking about just by looking at how your K31 ejects shells.

I'll be back when my Range-Rod has arrived.

HollowPoint

[Andrew Mason]

i have dream some day to take a ratty, beat up K31 and stub the original barrel and rechamber it in .376 steyr. i feel like it would be an awesome cast boolit rifle.

[HollowPoint]

i have dream some day to take a ratty, beat up K31 and stub the original barrel and rechamber it in .376 steyr. i feel like it would be an awesome cast boolit rifle.


The more I work on mine, the more potential I see in this rifle. Getting past all the misinformation about the difficulties of smithing these guns is the hardest part.

The Range-Rod I ordered finally found its way into my mail box on Saturday morning. I was able to use it to index the barrel for threading. I had already pre-indexed it off the outside diameter the day before. I thought it might cut down on the time it might take to zero it on the bore. I must have gone back and forth from the outboard and inboard points of adjustment for about 45 minutes till I got it turning as true as I could get it. I don't think it was really necessary but I was using my .0005" dial indicator. The .001" indicator would have sufficed; and probably cut that time down substantially.

The muzzle threads for my suppressor went off without a hitch. Right now I'm having some lunch but the chamber area or tang is nearly done also. I'll be ordering the chamber-reamer next week. While I'm waiting for that to show up I'll play around with the little ejector I mentioned in my last post.

I have a change-jar sitting in the bedroom. It's where I put all my spare change at the end of the day or week. Over the course of a few months it tends to add up enough that I can use it to buy metal stock, tools or other spare parts with. I counted it up the other day and it should put a big dent in the price of my Chamber Reamer. This time of the year I usually use that spare change to buy me a new hunting and fishing license. I figured this was just a little more important for now.

A few months back I wouldn't have been able to say this but, it really doesn't take much to bring a "Ratty" beat up K31 to the level of a rifle that anyone would enjoy owning. I've never heard of a .376 Steyr but, I have heard of dreams coming true. I hope to have my dream completed by the end of the month. We shall see.

HollowPoint

[Artful]

https://en.wikipedia.org/wiki/.376_Steyr


.376 Steyr


Type
Rifle / Hunting


Place of origin
Austria / USA


Production history


Designer
Steyr (https://en.wikipedia.org/wiki/Steyr_Mannlicher) / Hornady (https://en.wikipedia.org/wiki/Hornady)


Designed
1999


Manufacturer
Steyr


Specifications


Parent case (https://en.wikipedia.org/wiki/Cartridge_(firearms))
9.3 x 64 Brenneke (https://en.wikipedia.org/wiki/9.3_x_64_Brenneke)


Case type
Rebated, bottleneck


Bullet (https://en.wikipedia.org/wiki/Bullet) diameter
.375 in (9.5 mm)


Neck diameter
.3980 in (10.11 mm)


Shoulder diameter
.4732 in (12.02 mm)


Base diameter
.5010 in (12.73 mm)


Rim diameter
.4940 in (12.55 mm)


Rim thickness
.0500 in (1.27 mm)


Case length
2.3500 in (59.69 mm)


Primer (https://en.wikipedia.org/wiki/Primer_(firearm)) type
Large rifle


Ballistic performance




Bullet weight/type
Velocity
Energy


210 gr (14 g) XFB
3,011 ft/s (918 m/s)
4,229 ft·lbf (5,734 J)


225 gr (15 g) SP
2,910 ft/s (890 m/s)
4,232 ft·lbf (5,738 J)


250 gr (16 g) SP
2,754 ft/s (839 m/s)
4,211 ft·lbf (5,709 J)


270 gr (17 g) SP
2,610 ft/s (800 m/s)
4,085 ft·lbf (5,539 J)


300 gr (19 g) SP
2,388 ft/s (728 m/s)
3,800 ft·lbf (5,200 J)





http://www.stevespages.com/jpg/cd376steyer.jpg

Actually a very good choice for K31 build - but I'd lean to 358 WCF

[HollowPoint]

I suck when it comes to the metric system. What is the Maximum Average Pressure of the 376 Steyr? As long as it's within the capacity of the K31 action I think it would be a great cartridge too.

I've become a wuss in my old age. I don't think I could handle the recoil. That's why I went with the 6.5x55; and it has very moderate pressures.

HollowPoint

[Artful]

376 is 62K - your GP11 is 55K and the 6.5x55 is 51K
so it might be a little robust with factory ammo

[HollowPoint]

376 is 62K - your GP11 is 55K and the 6.5x55 is 51K
so it might be a little robust with factory ammo.

Are these PSI or CUP numbers? Not that I really know the difference but, some of my loading manuals list one or the other and this is how I figure out what may or may not be a safe choice.

Since the K31 action has been used to chamber 30/06's, 300 win-mags and 300 H&H, I'm fairly certain that the 376 Steyr should work safe enough. I'd still do a little more researching just to be sure though.

HollowPoint

[Artful]

Listed as PSI

300 win mag is 64K PSI / 54k CUP

[HollowPoint]

Listed as PSI

300 win mag is 64K PSI / 54k CUP

Thanks for clearing that up Arful. I still struggle with the PSI/CUP thing but if I know what the pressures are with each type of measurement at least I can make some comparative sense of it all.

Well: on the K31 project front, I was able to thread everything that needed to be threaded; the barrel, the Barrel-Nut and the Threaded-Barrel-Stub are all done and fitted as finely as I could get them.

I did run into another annoying but fixable problem with the threading on my Threaded-Barrel-Stub. When I went to try to test-fit it onto my newly threaded barrel I found that my threading tool must have had some flex to it when it reached the deepest part of the inside thread on that Threaded-Stub. It went on nice and slop-free for the first 3/4" or so then it got progressively harder the deeper I screwed it on.

I ended up having to "Chase" those inside thread from the opposite end of the Threaded-Barrel-Stub in order to bring them a little closer to the dimensions of that first three-quarters-of-an-inch that initially went on smoothly. Chasing outside threads is tricky enough as it is but, Chasing inside threads that you're trying to cut as "Class-3B" threads is even harder; especially when you lack the experience like I do.

I think that for an experienced machinist it would have been childs-play. More than likely, they wouldn't have made that mistake in the first place. Out of paranoia, I went about it trying to err on the side of caution. I left the those inside threads kind of tight to where I needed to use the leverage of my home made Barrel-Nut-Wrench to screw my Threaded-Barrel-Stub onto the newly threaded barrel. I still couldn't screw it on by hand but that's what I was shooting for.

Why? My thinking was that with tight fitting threads that weren't so tight that they wouldn't go on if I used my Barrel-Nut-Wrench, I could screw it on in the same manner that I would use if I were cleaning up poor or damaged threads with a threading tap. I screwed my Threaded-Barrel-Stub in and then backed it out; screwed it in and then backed it out, etc..

In the end I got some slope free snuggly meshing threads that I can screw in with hand pressure only. It took a heck of along time to do though.

On a positive note; the inside threads on my Barrel-Nut didn't have that problem. This is because I took the time to make a minimum of three identical passes at the same depth with each increase in thread depth. This mitigated the effects of tool flex. Unfortunately for me, I had learned the hard way.

I'll be taking some more pics tomorrow. I hope to be able to post them in the evening. I hope to be able to order my Chamber Reamer tomorrow as well. I'll be back with updates later.

HollowPoint

[HollowPoint]

One of the things that concerned me about having to turn down the chamber end of my barrel blank was the amount of wall-thickness I'd have to support my cartridge. As it turns out, that concern was unfounded.

Once I screwed everything together by hand, I found that the tenon area now actually had a little more supporting mass than the factory tenon did/does. This is partly due to the larger diameter I made my Barrel-Nut and my Threaded-Barrel-Stub. In addition, you'll note from the pics that the factory tenon only has about a two inch length of threaded chamber area before it reduces down to a thinner diameter.

The parts in these two latest photos are still kind of dirty. I really should clean them off better before I photograph them but, the pics were quickly done due to last minute work scheduling. Hopefully they'll give you a good idea what my previous post was attempting to describe.

I'm off to the bank to deposit my Chamber Reamer money, then it's over to the hardware store to pick up some roof sealer. It's been raining cats and dogs here and I found out last night that a small section of my roof isn't as water tight as I thought. I can't have water dripping on my machines.

HollowPoint

[Frank46]

Cannot wait until you get to range test this baby. Keep it up, looking good. Bet you're gonna get a few stares loading 6.5x55 Swedish into a formerly chambered 7.5x54 Swiss K31. Frank

[HollowPoint]

Hi Frank;

The funny thing is, any time I've taken my K31 to the range previously, it turned out that I was the only one there with a K31. Lots of guys have come by to ask what type of rifle it was. Several of those who came by to look at it stated that they owned a K31 but now that I think about it, I've never seen another K31 on the range anytime I've been there with mine.

Without fail, those who said they owned one also said that they loved their K31 but, they rarely ever shoot them. As far as military surplus guns go, I think I've seen more Mosin Nagant's on the firing line than any other milsurp. I know that one of the range masters is an avid K31 shooter. I suspect that if anyone notices the difference in cartridges, he'll be the guy; or, maybe not. At first glance, both the 6.5 and the 7.5 don't look all that different. I guess I'll find out when the time comes.

No matter; I too will be happy to finally get my K31 up and running. I ordered the chamber reamer on Wednesday. I have a light day of work today and it has finally quit raining for a while here. Hopefully I can finish up the outside turning of my barrel and set it up for cutting the chamber. I will also be setting up my Barrel-Nut on the mill in order to flute the outside diameter of it.

I have just a few more little things to do until I can finally see if it was all worth while. I was thinking the other night, "Man it would really suck if after all this work it blew into a million pieces when I took it out and proof tested it for the first time."

We shall see.

HollowPoint

[Frank46]

Think I might be the only one in my club that shoots the K31. Like you I've never seen another when at the local range. I have seen some match rifles built on the K31 action some years ago. Gunshop up in Pennsylvania had about 5 or so mostly in 30-06, 306 and 7.5x54 Swiss. Beautiful pieces of steel and wood. Only match rifle I have is a post '64 model 70 in 30-06 with the marksman stock. Funny thing about the '06 cartridge is that I find it easier to develop an accurate load either for hunting or match shooting. 55.5grs IMR 4350, rem or Federal case,CCI large rifle magnum primer and a 168 grain Sierra MK. I've shot that load in 3 '06 chambered match rifles all pre '64's, one 1949 Win model 70 standard in 30-06 and my latest '06 a Sako Hunter in '06. The Sako has a love affair with my dwindling supply of lake city 1967 match that I have. And suprisingly both the 168gr Sierra MK and the old 172 grain bullet as loaded in the match ammo group almost the same when fired out of the same rifle. There was a name used to describe what you are doing when you thread the barrel and fit it to a new breech section but cannot remember. It is a fairly known process and I've heard it being done on mannlicher schenaur rifles that had the 6.5 MN cartridge bolt head and they used a section of 7.62x39 bbl as both calibers share the same size cartridge head diameter. Don't think you'll have problems as long as you use the same pressure guidelines for the parent 7.5 Swiss. Frank

[Artful]

I saw a lot more K31's on the line several years ago when the swiss would still allow GP11 to be exported - now with them limiting what surplus ammo leaves it's become less of a shooter more of a collector.

[HollowPoint]

I saw a lot more K31's on the line several years ago when the swiss would still allow GP11 to be exported - now with them limiting what surplus ammo leaves it's become less of a shooter more of a collector.

I've never owned or bought a gun with the thought that it would be just a collector. I buy them to shoot them. If they sit idle for a while it's because I'm shooting one of my others and it will just have to wait its turn.

I only own three rifles and whenever I get the chance to get out and do some shooting it's hard to pick which one to take with me. It's like choosing just one of your kids to take out for a day of shooting while the others stand crying at the front window as they watch you drive off.

Once I get this rifle project done I'll then be the proud owner of a Tikka 223, an Enfield 30-303 and now this K31 in 6.5x55. The latter two are multi-tasker calibers. My 223 is more or less a plinking and predator/varmint hunting rifle. My problems is that once I develop a tack-driving load for any gun I own I rarely shoot any other load out of it. That's my reason for having three different rifles; one for coyote, one for mid-sized game and one for larger game. This makes it so I don't have to fiddle around with re-setting zeros on my sights.

I think I'm the only one who's like this. Once I dial a rifle in, I don't like messing with a good thing.

HollowPoint

[Artful]

Well, see you got an advantage of those who bought and now don't shoot - you reload!
Rolling your own makes a world of difference.

I got a 375 Weatherby magnum rifle and when I got it you could buy ammo
- then they quit making it
- now they are making it again.
http://www.budsgunshop.com/catalog/product_info.php/products_id/69221
http://www.midwayusa.com/product/965776/nosler-custom-ammunition-375-weatherby-magnum-260-grain-accubond-spitzer-box-of-20

If I didn't reload there would have been a long dry spell of shooting it.
You have to look at it from the point of view of the average surplus rifle buyer.
Most don't reload but buy the guns because the are reasonably priced and have
reasonably priced ammo to shoot up.

I remember when you could take a Benjie ($100) and pick up a mosin rifle and ammo and shoot for an afternoon. Heck I remember 308 at a nickle a shot.
Now you don't see 6.5x55 or GP11 for sale cheap but to you it doesn't matter.
You just Roll your Own.

You have a pretty good selection of stuff you can use from your 22, 264, and 308 rifles.

And I understand about one load one gun - makes life easier - I have a few rifles that are that way for me

- I also don't adjust the scope for range on those either, on those I have mounted the scopes with Duplex sights
http://www.nzhuntingandshooting.co.nz/attachments/f15/14382d1379330482-nikon-prostaff-4-12x40-matte-bdc-reticle-2031diagram-1.jpg
http://www.americanrifleman.org/articles/2011/12/8/working-with-duplex-reticles/

I hold the bottom of the top thick post for close range,
the cross hairs for that which falls within the "Point Blank" Range
http://www.deerhuntersclub.com/wp-content/uploads/2008/05/03-final_100-yard_trajectory.jpg
and then the top of the bottom thick post for my "Long Range" Shot.
And won't shoot beyond the Long Range distance.

[HollowPoint]

My Chamber Reamer showed up earlier than I expected so I spent the morning cutting my chamber. It worked out great. I won't spend alot of time explaining the obvious here.

I did have to borrow a loaded round of 6.5x55 from a friend just so I had something to use for confirmation on the depth of my new chamber. I think I got it right, even though the case heads from the various brass manufacturers tend to be ever-so-slightly different. This latest group of pics has some explanatory text superimposed onto it; just like the others.

The way things are looking right now I think that all I have left to do is flute the Barrel-Nut, Mark and Cut the extraction notch on my new barrel, Powder-Coat the last two components and then reassemble for proof testing. The Reamer arrived so quickly that I didn't have time to play around with the Ejector like I said I wanted to do. I'll get to that later. I'm anxious to see if this thing is going to shoot without coming apart at the seams.

With any luck, the next group of pictures I upload will include my fully assembled K31 chambered in 6.5x55 Swedish Mauser.

Tell me what you think cause I can't read your minds. Is there something I've missed? I've been racking my brain trying to think of anything I may have missed just so I don't find out the hard way later.

HollowPoint

[Frank46]

Just looking at your latest pics. On the 7.5mm barrel, that is some of the most intricate machining I've ever seen on a rifle barrel. Kinda makes you appreciate the mauser actions for their simplicty in fitting barrels. Looks like you used a Swedish M41 round with that tombac type bullet. Shot a bunch of those in more than a few of my Swedish mausers. Looks like you are well on your way to the home stretch regarding this build. Can't wait to see the test results. Now all you need is one of the Rocksolid scope mounts installed, but you did express a fondness for iron sights. Frank

[HollowPoint]

Back when I first started looking into the possibility of re-barreling my K31, one of the most commonly expressed observations about the K31's tenon configuration was along the lines of "Intricacy." The first time I was actually able to pull up a picture on the internet of the factory tenon of a K31, I just didn't see it that way.

In my mind the only thing that might qualify as "Intricate" is the angled-cam on the face of the breech. If you remove that from the equation all you're left with is a threaded cylindrical length of pipe with a couple of different outside diameters. Once you figure out a way to go about cutting the angled-cam to match the factory configuration, then the rest is just basic lathe work; at least that's how it seemed to me. Others may disagree, and they very well may be right but now that I've had a chance to work on it myself I can tell you, it's really not that complex. I think that the manner in which my written words have tried to describe it may have made it seem more complicated than it really is.

Another thing I looked into back when I was searching for info on re-barreling was, the possibility of mounting a scope on my K31. I found out about the off-center scope mount and further research lead me to the RockSolid scope mount. It looked interesting and exceptionally well made but it cost more than I paid for my rifle so I went about making my own. The RockSolid mount has an integral angled deflector that the empty brass ricochets off of when the bolt is pulled back. It requires a deliberate and brisk bolt pull back to build enough inertia for the brass to bounce off of and out the side of the receiver. Except for the angled-deflector, my home made scope mount works basically the same way; and it didn't cost nearly as much.

That's not to say mine is better. It was just cheaper for me. The RockSolid scope mount is made of steel. Mine is made of some scrap aluminum stock I had in my junk box.

If budget constraints had not played a part in this K31 re-barreling project, I would have bought the stainless steel barrel with the larger outside diameter and skipped the Threaded-Barrel-Stub part that led me to Plan-B. All I would have had to do then was thread and chamber my barrel blank and then make a Barrel-Nut to hold it in place. The cutting and shaping of the angled-cam would have been done in basically the same way that I did it this time around.

I wanted to ask about that loaded cartridge I used. The guy that I borrowed it from bought some in bulk. I don't really know what make or manufacture it is. You mention "Swedish M41." Can you tell me if they're boxer or berdan primed? The friend that I borrowed that from doesn't even own a 6.5x55 rifle. He told me he got a great deal on them that he just couldn't pass up so he bought them. He also said he could sell me some for cheap but if I'm going to spend more money to buy loaded ammo I want to get some I can reload. I'm not set up to reload berdan primed brass. I know it's possible to do but, if at all possible I'd rather get some brass I can hit the ground running with.

HollowPoint

[Artful]

M41 Prickskytte round was a Norma made bullet of approximately 143 grains.
https://www.msgo.com/attachments/m41-ammo-jpg.4556/
The standard M-41 ammo has a 2592 m/v in a 29" barrel.
Most every European military round I have fired was put up in a Berdan primed case.
It was said the rounds were made for M41B "sniper" rifle use.
http://d3axjxpyjk3o3s.cloudfront.net/sites/armslist/uploads/posts/2014/04/03/2898328_01_wtb_m41b_swedish_mauser_sniper_640.jpg
The best bullet to match that weight today would be Sierra's 142 grain "cruise missle" Matchking.
http://cdn6.bigcommerce.com/s-llwpiff/products/746/images/994/sierra_sra1742c_500rnd_400__45487.1433358643.480.4 80.jpg?c=2
I've seen the SMK used with 46.3 grains of RL22 with excellent results.

http://dutchman.rebooty.com/ammo.html

[HollowPoint]

Berdan primed; that's what I suspected but I wanted to be sure. I'll probably just by a box of commercially loaded ammo for proof testing. I hope I can find some on the shelves at one of our local retail stores.

I know I can get loaded ammo online, and it looks cheap enough but only till they add in the shipping fees. Then it becomes cheaper to drive around or call around to the local stores to see if they have any in stock.

I traded some of my 7.5x55 brass to one of our other members on this forum for some 6.5x55 brass just so I could start the process of working up loads. I may be getting a little ahead of myself. I really should have waited till I actually had a gun to shoot them out of but, I don't have the luxury of alot of pre-planned free time with which to do my load workup.

Speaking of Load-Workup, I also ordered a set of cheap loading dies. With any luck both the brass and the dies will arrive about the same time.

I'm hoping to do the last of the machining work on this K31 project next week some time. If I can find some 6.5x55 ammo locally I can use one of the upcoming weekends for proof testing my finished project. If I'm not mistaken, the surplus ammo is loaded to the pressures that the older surplus rifles were working under. Some of the new commercial ammo is said to be loaded for the more modern firearms that were built with better metallurgy.

I don't know this for a fact. It's just something I came across while in search of ballistics information. I believe the K31 action is more than robust enough to be able to handle the more stoutly loaded commercial ammo; if there is such a thing; and if such ammo does exist, that would be the thing to use for proof testing.

I also took the time today to Cold-Blue my new barrel. It actually looks pretty good; almost like I knew what I was doing. I intend to give it about four layers of flat-black spray paint for the time being. After I've proven to myself that it's going to function safely and reliably over the long run, I may take it back apart and Powder-Coat it too.

There something I was wondering about Powder-Coating a rifle barrel. Will or can the barrel get hot enough to melt that Powder-Coating with repeated firing of the rifle; especially since the barrel is sandwiched in an oven of two pieces of insulating wood-stocks?

HollowPoint

[Frank46]

All of the Swedish M41 ammo with the tombac bullet that I had was all berdan primed, same goes for a lot of the Lapua ammo that I had. Federal years ago imported Norma 6.5x55 under the American Eagle brand. That is boxer primed and does shoot very well in my Swedish mausers. Hansen Cartridge also did import 7mm, 6.5x55,303 British,7.62x39 and 7.62x54r years ago. If it has the green primer sealant it is boxer primed, red sealant and is berdan primed and possibly corrosive. I have a bunch of yugo NNY heavy ball 7.62x54r and my Russian M44 carbine loves it. Almost forgot the Hansen Cartridge company headstamp was either PPU or NNY. They also did import the 7.62x39 which was made in Israel with the IMI headstamp. You almost never see any of this at gun shows. Long gone. I only mention this just in case you run into some. Frank

[HollowPoint]

"If it has the green primer sealant it is boxer primed, red sealant and is berdan primed and possibly corrosive."

I've seen ammo with different colored sealants but I didn't know that they were meant to designate Berdan or Boxer primed cartridges. If this is the case, that means that the loaded cartridge that I used is Boxer primed. I had to do a double-take to confirm the color but it does have Green colored sealant around the primer. Are you sure about the colors?

If so, that means that I might have a source for cheap loaded Boxer primed ammo that I might be able to buy locally. And it would be re-loadable. The guy that I borrowed this cartridge from said he had made a bulk buy of the stuff and he might be willing to sell me some. I need to make sure it's the right stuff first.

HollowPoint

[skeettx]

To make SURE pull a bullet, dump the powder, look inside, then decap the case, and reprime with standard size primer.
YUP, INSURE!!

Mike

[Frank46]

The Swedish M41 6.5x55 cartridges as far as I know are all berdan primed. The new Serbian (formerly Yugoslavia) headstamped either NNY or PPU are boxer primed. Grafs sells the PPU brass and it's good stuff for reloading. Easy way to tell if the cartridge you have is berdan is pull the bullet,dump the powder and if boxer you should see one hole in the base of the case, if either one or two little holes then it's berdan. Frank

[HollowPoint]

I thought about pulling the bullet and checking but this is not my cartridge so if I do that I'll have to wait till I get permission from the actual owner. By then the brass I traded for will have arrived so I will have taken it apart for nothing; or maybe not. I'll just hold off for now. I was just trying to confirm the sealant dye theory.

HollowPoint

[Artful]

As far as I know there is no international agreement on sealant color - I've seen US military with black, purple, red and green.

[HollowPoint]

As far as I know there is no international agreement on sealant color - I've seen US military with black, purple, red and green.

Same here. I did a quick google search for any info on Primer-Sealant color codes but all I could find were color codes on the bullets themselves. It's not really that important right now. Heck, I don't even have a rifle to shoot them out of yet.

HollowPoint

[HollowPoint]

I finally got the chance to Flute and Powder-Coat my Barrel-Nut. It's been a while since I set up and used the 4th-Axis on my mill. The "Pucker-Factor" was definitely in play during this machining operation. Those of you who have ever crashed a tool on a metal working machine know what I'm talking about.

For you car guys; it's the physiological effect you get a mili-second before you accidentally put a scratch or a dent in your pride and joy and you knew it was about to happen seconds before hand. For you gun guys; it's the same when you take your new gun out for the first time and you end up scratching or dinging the finish somehow even though you were trying your hardest not to.

Pucker-Factor: Imminent catastrophe and there's not a damn thing you can do about it. It's when your butt-hole clinches down onto the fabric of your underwear so tightly as to create a molecular bond between the fabric of your fruit-of-the-looms and the cells that make up the skin of your sphincter . Yea; you know what I'm talking about.

All I have left to do now is mark and then cut my extraction notch in the face of the breech. I want to wait till my new brass arrives so that I have the exact type of brass I'll be loading to use as a sort of confirmation tool. I'd like to end up with a nice tight head space. It might mean that I'll be stuck with using the same type of brass from here on out but, that's OK. Brass of different head stamps can be a little different in measurement but not by that much so, this might be just much ado about nothing.

Here's a few more pics. This may be the last batch before I post one showing the completed project. By "Completed," I mean assembled in order to proof test it. I won't consider it really completed until I've had a chance to mount my scope and work up some loads.

I'll be back with updates as I move farther along.

HollowPoint

[taco650]

Looking good! Can't wait to see the finished rifle.

[HollowPoint]

Thanks Taco:

I was headed into the home-stretch but now I find myself swamped with work so I'm thinking it won't be till Thursday or Friday of next week till I can assemble the rifle. Who knows, I may get impatient and put it together after work or some time sooner.

I'm still waiting for my brass to show up. That's also one of the factors determining how long it is before I do the assembly. It shouldn't take that long to put together; it's just that there's no point unless I can confirm the head spacing I'm shooting for.

HollowPoint

[HollowPoint]

I'll be back after I've done my Proof-Testing. As always, your input is welcome.

HollowPoint

[skeettx]

YEEEE HAWWW
Safe testing and have FUN!!!!
Mike

[Frank46]

Great build and with excellent pictures and captions too boot. Can't wait until your proof testing is done and you shoot on targets. What scope mount is that if I may ask?. Old eyes have trouble with irons these days. Frank

[Cap'n Morgan]

Congratulations on a job well done!

[HollowPoint]

Great build and with excellent pictures and captions too boot. Can't wait until your proof testing is done and you shoot on targets. What scope mount is that if I may ask?. Old eyes have trouble with irons these days. Frank


Thanks guys; I'm glad to finally get this far on this project. I have a bunch of stuff I need to get caught up on around the house because of this project. (Mow the lawn, fix a roof leak, wash the truck, etc, etc, etc.) I'll be really glad when I get the Proof-Testing behind me and I can start some load work up.

The scope mount that Frank asked about is a home made number. I made this a few years back. If memory serves I also posted a thread on this site of that scope mount build. Back then when I looked into scope mounts for the K31, I came across alot of posts on the internet stating that it was next to impossible due to the upward and back ejection of the brass from a K31. I hate hearing folks tell me that something can't be done; especially when it's evident that it can be done. I had to alter it from its previous shape in order to get it to fit on this new Barrel-Nut setup.

When I initially made it, it was longer so that the front end extended far enough forward to fit into the trough where the factory rear site fit into. With the factory rear site removed, the scope mount was secured at the front with the same cross-pin that secured the factory iron site. All I did was cut it back just enough for the front edge to sit directly on the shoulder of my new Threaded-Barrel-Stub where I had drilled and tapped two holes. Those two holes are now the anchor points for the front of the scope mount.

HollowPoint

[Frank46]

HP, thanks for posting pics of your scope mount. Much appreciated. Frank

[44magLeo]

Very interesting read. The only thing I can say is on metric threads. At one point you said the stock barrel threads were 2.0 mm TPI. On metric threads they are not TPI. The 2.0 mm is the distance from one thread to the next.
I tinker old Japanese motorcycles, I understand metric threads.
On your friends 6.5x55 ammo, go a head and buy some. It won't hurt the rifle, unless it's corrosive, even then if you clean it shortly after shooting the corrosive ammo it won't corrode the barrel.
Leo

[HollowPoint]

Very interesting read. The only thing I can say is on metric threads. At one point you said the stock barrel threads were 2.0 mm TPI. On metric threads they are not TPI. The 2.0 mm is the distance from one thread to the next.
I tinker old Japanese motorcycles, I understand metric threads.
On your friends 6.5x55 ammo, go a head and buy some. It won't hurt the rifle, unless it's corrosive, even then if you clean it shortly after shooting the corrosive ammo it won't corrode the barrel.
Leo
Frank; your welcome.

I'd have to go back and re-read that particular post but I thought I said something like, "2.0 mm per whatever" cause I didn't really know how to write it correctly. I also recall admitting that "I Suck when it comes to the metric system."

I did get a chance to load ten rounds of 6.5x55 ammo for test purposes. Four of those rounds will be full power loads of 120 grain Barnes TSX lead free bullets. I don't know if it's true or not but I've read and I've heard that these particular bullets impart a little more friction as they travel down the bore compared to conventional cup and core bullets so, with a max load of powder, if this is true these loads should be just slightly higher pressure enough for me to consider an appropriate Proof-Load. Last thing I want is overkill.

I'm not really afraid of shooting or buying the ammo that my friend loaned me. It's non-corrosive ammo. I just prefer to start with the brass, primers and bullets I'd be using routinely.

The other six loads are a full grain-and-a-half lower just for the heck of it. I'll probably start out with those lower charge weight rounds. All I need now is some free time to make the drive out to the desert. I also have to round up some bunji-cord. When I proof tested the Enfield that I re-barreled I used bunji-cord to secure it to a couple of limbs of a mesquite tree with a long length of twine to pull the trigger with. I know it's kind of goofy sounding but, that's just how I do it. I'm sure there's probably better ways of doing it but, I don't want to have to pack all kinds of stuff just to go out and fire ten rounds.

HollowPoint

[taco650]

Hollow point,

One thing I've really enjoyed about this thread are your photos with the captions. They have really helped me understand the technical details you were trying to accomplish in this build. Your photos are pretty well done too, not grainy and poorly lit. THANK YOU!

[HollowPoint]

Thanks taco:

I may get brave and do a slide show type of video to post to my YouTube account. I'm still mulling that over. In all my searching for this type of information on the internet, I never once came across any kind of documentation on how to actually do a re-barreling job on a K31.

If I were to post such a video, there's a chance I'd be the only one to ever do so but, since I have it on good authority that "There Is No New Thing Under The Sun," perhaps there is such info on the internet; I was just never able to find it.

Back in my college days I took enough courses to acquire certification in "Digital Imaging." I rarely ever use what I learned any more except in write up like this one. Those college courses trained in the use of PhotoShop and other photo editing software. Also; I had to take several photography classes as a part of that curriculum. I actually did photography for a couple of year before I came to the realization that it was much more fun doing it as a hobby than doing it for a living.

I'm glad the photos came out clear enough to understand. I had to use the lowest quality settings just to fit them into my allotted space on this website; even then I still had to go back and delete alot of the pics I had uploaded from many of the other threads and projects I posted here. I'll eventually take these photos down too.

HollowPoint

[Frank46]

HP, one caution about 6.5x55 ammo. The Danish made some with cupro-nickle or copper nickle jackets and the bullet weight was around 160 grains. These bullets are notorious for leaving lumps of the bullet alloy in the barrel. And there have been a few kabooms due to continual shooting this ammo. The headstamp is as I recall HA 48 with a triangle and they are corrosive. So if you are offered some don't waste your money. The Dutchman should have some of the info on his website. You spent good $$$ on your K31 so please accept this as a friendly warning as this stuff is still out there. Frank

[nekshot]

I applaude your skills and that is a lovely swiss rifle with a bit of "swede" mixed in it!

[HollowPoint]

Thanks Everyone:

I appreciate you compliments and cautions.

HollowPoint

[HollowPoint]

OK; I'm just messing with you.

I finally got a chance to make the 85 mile round trip to the desert to Proof-Test my newly re-barreled and re-chambered K31 Swiss.

I drove all that way and I forgot to take my length of cord to act as my remote triggering device. Fortunately, I had a piece of upholstery fabric in the back of the truck that I cut into several tied-end-to-end lengths to form my length of cord. Improvise, Adapt and Overcome; and I'm not even a marine; just a forgetful home gunsmith.

I decided to install my scope mount after all; without the scope on top. I think it was out of a certain sense of paranoia. I figured if my K31 was going to fly apart that little bit of added mass might keep me from having to scour the desert floor in search of all the pieces of my rifle.

The lower powered rounds were fired first and upon inspection, both the empties and the rifle looked none the worse for wear. The brass ejected positively every time. When I fired the full power loads, a bit of effort was needed to eject the shells. Slightly flattened primers and the effort needed to eject them showed that they were indeed slightly over pressure but, the K31 showed no signs of trauma.

I installed my suppressor and fired one full power load and the four lower powered loads I had left. That last full power load required me to remove my rifle from the rifle-rest in order to get the leverage I needed to extract and eject that particular shell. That, for sure was an over pressure load but, it did extract and eject as it should and the K31 kept on ticking.

Since I had the rifle out of the rifle rest, I got brave and decided to fire off the remaining cartridges off-hand. With the suppressor still in place the recoil was minimal; I'm not kidding, it was really mild. And get this; when I fired those off-hand rounds I was using the channel I milled into the top of my scope mount as a sort of rudimentary rear sight. My aim was at beer bottle about 30 or 40 yards away. Each point of impact at that distance was about 7 or eight inches to the right and low by the same amount. I hope it's an indication that I won't have to fiddle around to much with getting my cross-hairs on paper when I mount my scope.

Here's some more good news; I took along my cheap little handy dandy hand held video recorder to document it all. It's poorly shot with grainy images but I thought that with all of the exaggeration and flat out lies we read about on the internet it might be a good idea to have some real world proof to back up my claims of having re-barreled and re-chambered my K31 myself. And I have to tell you all, it wasn't as complicated as some of the internet experts made it seem.

I have yet to edit the video in order to upload it to my YouTube account. I'll try to do that this weekend and then post it to this same thread reply.

As I've already stated, the video itself is poorly made. The angles aren't the best but there's enough visual information there to confirm that the claims I made throughout this project-thread were true. The audio kind of sucks so you'll have to turn up the sound on your browser in order to hear. Another thing is, when I fired these loads with the suppressor on, I put the camera about three or four feet from the muzzle so it still comes across incredibly loud. In reality they sounded more like a 22 rimfire round being shot.

One last thing about this upcoming video; when I fired each round the video appears to show an awful lot of recoil for such a "Mild" recoiling rifle. This is because the rifle was recoiling as I was simultaneously pulling back on my length of remote trigger cord. In effect, I was pulling the rifle back farther than the actual recoil would have made it appear. Another thing is that although I'm shooting my K31 off hand for the last few rounds, the camera angle is such that all you can see is from my armpits down. Sorry about that. You'll just have to take my word for it.

I'll be back when I've edited the video.

HollowPoint

[taco650]

The sweet smell of success!! Just like burnt gunpowder eh? Congrats on a successful project wrap up!

[HollowPoint]

Thanks taco:

I'm uploading the video I mentioned before onto my YouTube account even as I write this reply. It was such a massive video file that I had to chop it up even further just to get it down to an up-loadable size. Even then it was still a massive file. It's taking me over a half hour to upload on my slow internet connection.

I hope it comes across clear enough to make some kind of sense. Now it's on to the load work up stage of this project. I don't know if this is cocky or confident but, I get the feeling I might end up with a tack driver on my hands.

When I got home for Proof testing yesterday, I found that my Globe-Front-Sight was not actually tightened down onto my barrel. It was loose and tilting ever so slightly to the left. The bayonet-lug-thingy was the only thing keeping it from tilting any further to one side or the other. This was most likely the reason my points of impact were repeatedly low and to the right; but almost to the exact same spot. I'm hoping this means that I clocked the barrel just right to give me a straight shooter once I mount my scope. I'm hoping for the best.

I'm thinking that if there's enough guys out there who have dreamed of re-barreling their K31's and enough of them undertake such a project, it might very well drive the price of a K31 rifle through the roof. Now that folks know that it's not as difficult as it was made to seem to change over to a more common caliber, it could give the K31 a resurgence.

HollowPoint

[HollowPoint]

Here's a small amount of proof for those who followed this project thread confirming that you were being told the truth at every turn.

Best of luck to any and all who may undertake the same project with their own K31 rifles.

I'll be back to dredge up this thread once I've had the time to do some load workup. Wether the results are good or bad, I'll let you know.

HollowPoint


https://www.youtube.com/watch?v=_lr2IIkp4s0&feature=youtu.be

[taco650]

The suppressor worked really well.

[HollowPoint]

I use this particular 30 caliber suppressor for my 223, my 30-303 and now the 6.5x55. It's user serviceable so I can shoot cast lead bullets and I'm able to take it apart for cleaning. Lead loads tend to line the inside with a thin layer of lead if I don't clean it after every use. That was my main motivation in picking this brand. It's a Lane Scorpion King Suppressor.

I thought it would make my K31 nose-heavy but because of the added mass of the parts I had to fabricate when I re-barreled, the suppressor kind of balances the rifle when shooting off hand. Overall, my K31 is heavier. I put it on a scale after I mounted my scope and it weighs a little over 10 pounds. In its factory configuration it already weighed a bit over nine pounds. The scope and alterations just upped that measurement.

HollowPoint

[Artful]

Congratulations - and thanks for the video

[Frank46]

Really enjoyed your testing and sad that now it's over. Besides the machine work you had great pics and captions as well. Been a good ride with you with the build. Congratulations on your 6.5x55 swedish/swiss K31. Frank

[leebuilder]

Well done thanks for sharing.
Be well

[HollowPoint]

I get an email notice in my inbox every time someone writes a reply on this thread. I feel like I'm ignoring you if I don't post a reply to your replies.

Many thanks everyone; and you are welcome. I've appreciated your comments throughout this project. One of the things I was hoping for by posting this project on this forum was to hear thoughts and suggestions from the many lurkers who must have been following this thread.

I say "Many" because at last count there was a little over five-thousand views on this project. I don't believe the tracking system on this site re-counts the clicks of the same person clicking on this same reply over and over again so, this leads me to believe that I'm not the only dreamer with ambitions of smithing their own K31 or other rifle.

Imagine all the brain power if all the lurkers had chimed in at some point. I'll admit I've been back here at least once a day during this run. It was either in the early morning before I was off to work or at lunch time while at work. It's been a fun ride for me too. Unless it's to reply to one of your replies, I most likely won't be on as much until I've had a chance to work up some loads. If this thread is lying dormant I'll dredge it up to post my updates.

Thanks again everyone.

HollowPoint

Tim M.

[McFred]

I'm happy to see you've completed your project, though to be honest I was surprised to see that you didn't make your own suppressor on an ATF Form 1. You're obviously a competent home shop machinist and suitable materials and tooling are plentiful, it's that tax stamp that's hard to swallow.

Thanks for the video and posts on your progress.

So, now that it'll hold the pressure, how's she group? ;D

[HollowPoint]

Thanks McFred;

I did dream of making my own suppressor. I'm pretty sure I could but I was less than confident when it came to filling out all the paper work and jumping through all the hoops required to actually acquire or build a suppressor. One of our local guns stores is set up to help new buyers fill out and send in a Trust form so I went that route for convenience sake.

A few months back I started hearing of the possibility of a law passing that would do away with that pricey tax stamp. Something called the, "Hearing Protection Act." I haven't heard anything more about it since. I guess the anti-gun folks have managed to sweep that under the rug. If such a thing would have come to pass, it would have been the closest thing to getting a free suppressor for me that I can think of.

I loaded up my first batch of cartridges for my Load-Workup. It's just a matter of finding the free time to go out and do the testing. I'll be back with updates once I get some range time under my belt.

HollowPoint

[Artful]

The bill proposed would still have required a tax (just $5) and still the same paperwork and wait period. A step in the right direction but I don't think you'll see that boot get in the door.

Building the suppressor itself wouldn't be hard for you. But you would want to consider which materials and design to use, and that can be a vexing issue with some of us.

[HollowPoint]

"Building the suppressor itself wouldn't be hard for you. But you would want to consider which materials and design to use, and that can be a vexing issue with some of us."

I agree with you a hundred percent. I guess I'll just cross that bridge if or when I come to it. Five bucks isn't that bad though. It would sure take some of the sting out of that wait time; although paying only five bucks will probably increase the number of folks applying and thereby increase the wait time too.

Actually, if I were to build my own I figured I'd just clone the suppressor I have now; materials and everything. It's an easy design to copy. The only difference would be the diameter of the thru-hole.

HollowPoint

[HollowPoint]

I finally got a chance to get to the shooting range to fire off my first batch of loaded 6.5x55 rounds for testing accuracy potential of my newly re-barreled and re-chambered K31. Finally!

It was freaken-cold at the range and I was shivering like a little old lady in Antarctica without her sweater. I'm not kidding; a quick glance down the firing line gave the appearance that everyone there was smoking cigarettes. With each exhale of breath a plume of smoke was released.

Anyway; following is a list of my components:

Powder- IMR 4831 Why? Because, in my reloading manual this particular powder showed the lowest pressures and highes velocities ratio with bullets of 120 grains or heavier. No other reason.

Bullets- The bullets I used to get my hits on paper were kindly sent to me by one of our other members, Bert2368 (http://castboolits.gunloads.com/member.php?8227-Bert2368) when we did our brass swap. He sent me out about twenty or so 120 grain Barnes lead free bullets. They're excellent bullets but, they are above my pay grade in terms of repeat usage. I went with the much cheaper 120 grain Nosler Ballistic Tips to ensure I could still afford them down the road.

Primers- Standard CCI 200 Large Rifle Primers

Brass- Privi-Partisan once fired, full length sized


I used up six out of the ten Barnes sighter bullets to zero my scope out to fifty yards. From there I used the last three to zero at a hundred yards. On top of 47 grains of powder, those Barnes bullets came darn close to MOA shooting that far out for the first time; and keep in mind that I was shivering like a little old lady.

From there I started firing my intended loads. Points of impact were about an inch farther to the left with the 120 grain Nosler bullets compared to the points of impact of the Barnes bullets. I didn't adjust my scope to compensate until after I'd fired all my shots. I just kept putting my cross hairs on the bullseye of my targets.

I did take pictures to prove my claims. As of this writing I haven't had time to size them down for uploading. I'll try to get to that tonight. I know this sounds like a BS-excuse but, I wish it hadn't been so cold. Most of my first and second shots at each successive charge weight were making me real happy. Then I'd pull the third shot just enough to make me feel like an incompetent-shmuck of a marksman.

I would like to brag a little at this point. Extraction and Ejection were flawless. At the maximum charge weight, the Nosler bullets didn't require nearly the effort that was required to extract and eject the max-charge-weight Barnes lead free bullets. I think it was because the more conventional Nosler cup-and-core bullets didn't create as much pressure within the chamber as the Barnes bullets did.

One final note on load work-up. I use the "Optimal-Charge-Weight" (OCW) method of working up loads; as apposed to the "Ladder" method. I won't try to explain how that method works here. If you're interested you can google it for greater detail.

These are the photos I took of my Load Work-Up results.

I mentioned above that my sighting shots with the 120 grain Barnes lead free bullets were darn near MOA. Upon closer inspection it turns out that I was wrong. They were in fact sub-MOA for a three shot group.

I know that some will say that it takes five or more shots to confirm such a claim but, at this point it doesn't really matter to me. I was just there to perform my initial work up and these were my results.

The Nosler 120 grain Ballistic tips would have fared just as good if it weren't for pilot error. I'm confident I can do better. I've determined that the two highest charge weights will be the ones I'll be tweaking in search of bug-hole accuracy.

Those tweaks will be in the form of OAL adjustments. The targets on the left are one-inch-squares with circles in the center of them a little under 7/8" in diameter. The targets on the right are two-inch outside diameter circles. I just wanted to give you some sense of scale on these targets.

HollowPoint

[taco650]

Your targets prove that everything works and works well. The 47.3 charge appears to be the best of all you've shown. Guess you'll be tweaking the scope to the right a bit. Even the Barnes bullets show "left leanings" LOL!

What did you manuals say about Reloader 19 or 22?

[HollowPoint]

My manuals don't include any of the Reloader powders. It's more of a specialty Hodgdons magazine type of reloading manual. I have several of them and since it's put out by Hodgdons, they tend to stick to loads that mainly highlight their products.

If you'll notice in the pic on the right; the impact points of the first and second shot strings are in approximately the same area. The same holds true for the third and fourth shot strings; as well as the fifth and sixth shot strings. What I'm looking for with this method of load work up is points of impact as apposed to one tight little cluster out of all the shot strings I fired.

Just for arguments sake, if I hadn't pulled the third shot on each of the shot strings after that 47.3 shot string then the 48.2 and the 48.5 grain shot strings would have clustered into about a one inch cluster. (in optimistic theory) When I load my next batch of load work up rounds I'm going to load them with a charge weight of 48.35 grains of powder.

Why? Because at 48.2 and 48.5 grains my bullets are impacting at about the exact same spot. This means that when I reload my cartridges I have some forgiving leeway both above and below that charge weight of about .15 grains of powder and the corresponding pressure increases or decreases that little bit of powder would induce.

I don't know if I'm explaining that correctly or not. For a better explanation you can do an internet search for "Optimal Charge Weight" method of load work up.

I already know that with a charge weight of between 48.2 and 48.5 my bullets impact at or very near the same spot. With the next batch of loads, I'll load three more of each with the same 48.35 grains of powder but, after the first three shots I'll be extending the overall length of the cartridge by .005" until I reach the max length that will fit into my rifle's magazine.

My hope here is that one of these differing OAL's will be the sweet spot that will give me the Bug-Hole accuracy I'm looking for. I know it's possible. I've done it before; just not with a rifle that I've re-barreled myself.

I'll be back to post updates once I've gotten the chance to get to the range again.

HollowPoint

[gzig5]

Congrats on a very nice project. You showed a lot of ingenuity in copying the cam surfaces. I've got two K31s, one as-issued and one I fully bedded the action front and rear. The bedded one will shoot 5/8" c-c 100yd five shot groups with boring regularity with a set of original Swiss clamp on aperture target sights. You are early in your load development but the groups show vertical and you might need to tweak the bedding. As you probably know, these rifles are sensitive to the rear action screw tension if they aren't glass bedded. The barrel should not touch the forend for best accuracy too.

Could you show some more detail of the shell deflector on the scope mount? I've been wanting to mount a scope but don't like the offset mounts available and the offset causes issues with windage at long range (800-1000yds). I want to shoot it in a scoped NRA Long Range match and see how it does compared to the modern dedicated rifles.

[HollowPoint]

Hi gzig5; and thanks.

I bedded my K31's action back when I first bought it. I used AcraGlass. At the time I thought I had really screwed up because after bedding it I was unable to separate the action from the stock. For the longest time that's the way I shot it; and it shot pretty darn good too. When I decided to re-barrel I thought to myself I most likely would have to ruin the stock in order to remove the action but, since I was re-barreling I'd just have to bite the bullet and find a new stock for it.

As it turned out, the reason I had such difficulty in separating the stock from the action was due to the recoil lug on the K31's receiver. It's so big and deep, compared to conventional rifles that it created a sort of suction effect when I tried to separate the two. I finally did separate the stock from the action by a rocking motion from front to back. The fit of my bedding job was just super tight. I also added home made aluminum pillars at that same time and free floated the barrel from the face of the receiver to the tip of the muzzle.

I did notice the last time I had the upper stock section off that there was a light contact mark present. Some of the black powder coat finish had rubbed off enough to leave a tell tale sign. I'm going to have to take that upper wood off again to check and see if my sanding efforts had truly resolved that contact problem. I prefer zero contact as far back as I can get it. Right now I should have no contact between the wood and barrel back as far as the front face of my elongated barrel nut. I say "Should Not Have" because I still need to re-check that spot on the upper wood stock to confirm.

I'm kind of reluctant to remove my scope in order to show detailed views of how my shell deflector works. I'm just now getting it dialed back in. I'll see if I can't get good photo angles so as to show how it's designed to work. It's a real simple setup; it's just that trying to describe it with the written word makes it seem a whole lot more complicated than it really is.

In my very first attempt at this "Deflector Design" I actually made one that hung off of the scope itself. Eventually, when I made my present scope mount, I incorporated this pivoting deflector design into the scope mount instead of running the risk of the impact of the empty brass possibly damaging my scope.

I'll see what I can come up with in terms of pictures.

HollowPoint

[HollowPoint]

I mentioned in one of the posts I made on this thread that there was no way I could afford to pay a gunsmith to do this same amount of work on my K31 but, I was wondering after the fact, how much would a known and competent gunsmith have charged me to do this work? I'm asking because I don't really know. The only thing I do know is that I couldn't afford it.

Would anyone care to guess; just to give me some idea? When I did my research into this project before hand I came across some exorbitant numbers that were alluded to but, no real world estimates. I'm just curious as to how much money I might have saved myself by doing it myself.

HollowPoint

[Artful]

Most Gunsmithing is at least $50.00 per hour - how many hours of actual work did you need to complete it?

[HollowPoint]

Most Gunsmithing is at least $50.00 per hour - how many hours of actual work did you need to complete it?


If I don't include any time I spent waiting for tools or parts to come in I'm thinking it took about 40 hours or so of actual work. I didn't really keep track of time in a dollars-per-hour sort of way. It just seems like I did a weeks worth of work; possibly a little more due to my inexperience.

I'm thinking that an experienced gunsmith or machinist could probably shave some time off of that but, holy cow man; at $50.00 an hour is it really two-grand worth of parts and labor. Maybe I did save myself some money after all.

HollowPoint

[skeettx]

YES, and not only that, most gunsmith would NOT have undertaken that project!!!!
You have a winner!

[Frank46]

Labor of love is what I would call it and expenses come second. Frank

[gzig5]

There was an article years ago, I think in Precision Shooting about a guy that had a K31 converted to .358 win with a nice new stock and scope mount. Essentially what you have done on yours. I don't recall if they got into the specifics of how the barrel cams were done but I believe that rifle cost the man more than $5,000 and it could have been as much as $8,000 I just don't recall. Now much of that was in the stockwork, which nowadays a full custom stock from one of the big names runs in the $3-5000 plus wood costs.

[HollowPoint]

Well; at least part of what I'd heard about working on K31 seems to be true; that is, if you pay someone else to do the work for you. Those multi-thousand dollar figures are just mind boggling to me. How many of you guys could afford to pay that much? I know I couldn't.

On a side note: I have my next batch of loads all ready for testing. They are all loaded at 48.3 grains of IMR 4831 powder. I'll be starting off with four cartridges put together at the same OAL as my original batch, followed by four rounds with an overall length of .005" longer; followed by another four rounds .005" longer etc. until I've reached the point where they will no longer chamber due to the throat dimensions or to the fact that they will no longer fit in my magazine.

Actually, If I remember correctly I'm going from an OAL of 3.026" up to 3.051" in .005" increments. That still leaves plenty of room in my magazine for further length. If I don't find a sweet spot within that OAL spread I'll do one more batch with slightly longer overall lengths and then call it done. I've already gotten some promising results with my initial tests so I'm confident that I'll eventually find that bug-hole accuracy I've been longing for.

Now it's just a matter of finding the free time to get to the range.

HollowPoint

[Artful]

Better hurry - I went out yesterday and I needed my sun screen and was wishing I took something for shade. Didn't even make it thru all my ammo before it got the best of me.
Of course it was 9:30 before I got to the shooting spot.

[HollowPoint]

Here in AZ it seems like there isn't even a transition time between the summer, autumn or fall seasons anymore. One day its cold, next day it's cool; followed by warm then on to hot. Then we get into the really hot weather.

When I went out for my initial load testing it was cold enough to exhale smoke. Now it's in the mid to upper 80's. I may not be able to get out to test the next batch of loads till the week after next. It might be in the nineties by then, who knows.

I would have loved to have gone out this weekend. The weather was perfect; not to cool and not to warm. The good thing about the method of load work up I'm using is that it allows for fluctuations in temperature; which in theory, can affect pressures.

HollowPoint

[gzig5]

Come on, quit your b****ing. :) We had a high of 8 degrees yesterday and when the kids started ski school class in the morning, it was 0 with -15 wind chill. I've been waiting a couple weeks for it to get above freezing so I can get a few hours testing in for my spring ground squirrel trip.:cry:

[HollowPoint]

Being born and raised in Arizona, it's hard for me to even imagine it being that cold. I was in Texas one year during the New Years holiday and it got pretty cold then but, no where near the temps you mentioned.

Even then I found it hard to walk a straight line because I was shivering so badly. I must have looked like a drunk guy trying to find his way back home.

HollowPoint

[Artful]

I've paid my winter dues in PNW - and if I want snow I can drive to it up on the Rim.
There's a reason people retire here to Arizona [smilie=s:

[taco650]

I've paid my winter dues in PNW - and if I want snow I can drive to it up on the Rim.
There's a reason people retire here to Arizona [smilie=s:

Save me spot Art LOL!

[HollowPoint]

I recently sent off an email to the only person I can think of who might be able to answer this question. After I pushed the "Send" button it occurred to me that someone on this forum might have that info as well.

Although I'm kind of reluctant to ask this type of question on any gun related forum I belong to because it tends to open up a can of opinionated worms without ever really getting the answer I'm looking for, I thought I'd ask anyway in hopes of shortening my research time. The question to which I seek an answer is written in bold lettering below.

Following is a cut and paste of the email I sent to Larry over at lprgunsmith.com (http://lprgunsmith.com/):


Greetings From Arizona:

I'm considering re-barreling and re-chambering a yet to be purchased K31 to a higher pressure-rated 6.5 caliber cartridge. In researching the Maximum-Average-Pressures of this particular cartridge it occurred to me that the Max pressures being referred to by SAAMI, CIP and others pertain to the cartridges themselves; not to the actual strength of the receiver that will be used as the platform around which this cartridge will be fired.

Thus far in my research into the strength of the K31 action I've found that reputable outfits like Hamerli and others, including yourself have re-chambered the K31 actions in various calibers with higher Maximum-Average-Pressure ratings than the 7.5x55 Swiss cartridge native to this rifle.

Do you know of any specific documentation listing the actual Maximum-Pressures that the Swiss K31 receiver/action is able to safely withstand? Perhaps an easier question to answer would be, what is the highest Maximum-Average-Pressure rated cartridge that you've safely re-chambered a K31 action for?

I successfully re-barreled and re-chambered my first K31 a few months back but, it was done in a cartridge with a slightly lower Maximum-Average-Pressure rating than the 7.5x55 Swiss cartridge. From that experience I now have the confidence to do another. This time I'd like to go with the 6.5x284 Norma cartridge but, only IF I can confirm that it's safe to do so in a K31 receiver.

Thanks in advance for any help you can share.

Tim M.

[taco650]

Why not go the other direction and re-barrel to 35 Whelan or 358 Win?

[gzig5]

There were factory commercial target versions of the K31 available in .308 Win, 30-06, and 300 Win Mag. I would say that it should be able to handle any modern cartridge that goes up to those levels. I don't think I'd want to muck with a magnum size bolt face conversion though, and primary extraction with a straight pull bolt can be challenging with hot loads that wouldn't pose a problem a bolt action. I wouldn't think that a 6.5x284 would be a problem at all. I load my 7.5x55 to 30-06 pressure levels (based on velocity readings and similar case capacity) and haven't had any issues. It's a strong action.

[HollowPoint]

There were factory commercial target versions of the K31 available in .308 Win, 30-06, and 300 Win Mag. I would say that it should be able to handle any modern cartridge that goes up to those levels. I don't think I'd want to muck with a magnum size bolt face conversion though, and primary extraction with a straight pull bolt can be challenging with hot loads that wouldn't pose a problem a bolt action. I wouldn't think that a 6.5x284 would be a problem at all. I load my 7.5x55 to 30-06 pressure levels (based on velocity readings and similar case capacity) and haven't had any issues. It's a strong action.


I agree with you completely but, being that I'm not a gunsmith, I needed to make sure. I also posed my questions over on the Swiss Rifle forum and got basically that same response.

taco650 asked, why don't I go the other way and chamber in a 35 or a 358? Well, after shooting the 6.5x55 cartridge and feeling how pleasant it is on my shoulder, I've developed a liking for this lighter weight projectile.

Following is the reply I posted over on the Swiss Rifle forum where I received a similar response to that of gzig5.




I'm not an expert in these matters but, these were my thoughts as well. I needed to make sure before proceeding with such a re-chambering. In my mind I pictured any number of more modern rifle actions; both long and short actions that are used for everything from the 17 remingtion to the most powerful magnums. With this in mind I figured there was a fair likelyhood that the K31 action could handle the pressures of the 6.5x284 Norma cartridge.

I woke up this morning to find an email reply from Larry Racine in my inbox. He also confirmed what I'd been hoping. In addition, he stated that among the re-chamberings he'd done on K31's were cartridges like the 308, 260 and the 284; which incidently, is the cartridge that the 6.5x284 is based on so, there you go. There was a cautionary note regarding the slightly higher pressures causing instances of case stretching and poor extraction but, I'd already experience this when I rechambered to 6.5x55 Swede.

I found that the max charge weights tended to display these symptoms to where full length resizing was needed in order to reload that particular brass. Those loaded with charge weights just below max could be neck sized only before reloading. As luck would have it with my K31, the most accurate loads have been just below maximum charge weights. I'm still working up loads but things look real promising.

It will be a couple more months before I have the money saved up to buy another K31. For now, I can start with getting all my other ducks in a row; like loading dies, chamber reamer, brass, etc.

I'm kind of hoping that these K31's haven't become like a crack-addiction now that I have a little experience with smithing them. The 6.5x284 was the original caliber I wanted to re-chamber my previous K31 in but I was afraid that the receiver might not be able to withstand the pressures.

Now I know better.

HollowPoint

[HollowPoint]

It's been a frustrating few weeks of waiting for some free time to come up so I can get to the shooting range and carry on my load work up. I have had a few days open up but they are immediately filled with more pressing matters.

During this wait time I've been tinkering with my brass ejector in between jobs. I thought I'd try to figure out a way to get my original design to function reliably without having to pull the bolt back as briskly as I've had to in order to eject the brass out the side of my K31.

I went whole-hog on a completely new Overly-Complicated design that turned out to work only half the time so I eventually came back around to my original design. I ended up video recording the ejection cycle and playing it back in slow motion in order to see exactly how my empty brass was moving as it made contact with my home made ejectors.

I should have done that video thing a long time ago. It would have saved me alot of work. The final tweaks I made to my original design were so simple once I knew exactly what angles my ejector had to be in order to guide that empty brass out the side of my receiver that I could have kicked myself for taking the long road on this project.

I'm including a few poorly shot photos of some of these tweaks for those of you who have considered mounting an inline scope and scope mounts. These types of home made ejectors can help with the problem that arises due to the straight upward ejection of the factory K31 rifle. I tried the offset scope mounts but I just couldn't get used to them so I went with an inline scope instead.

My ejector is made to attach to my scope mount but the very first ones I made were made to hang from the bottom of my scope via some modified scope rings.

Pardon the krapppy pics. Now I have to go back and clean all the dust and dirt I manage to get into my rifle's action while I was working on this ejector tweak.

HollowPoint

[HollowPoint]

It's hard to believe that months have past since completing this K31 project. I see from the number of views this thread has gotten it's now creeping up on Ten-Thousand clicks. I guess I really wasn't the only guy on the planet who had dreamed of re-barreling or re-chambering their K31 rifle.

After all of these past few months I finally got the chance to get out to the shooting range to test that second batch of reloads I'd been working up. Before I did that I went back in and I adjusted my head-spacing by .003". I found that with the stiffer loads it was looking like my primers were flattening out but, I found later upon closer inspection at the reloading press that my primers were actually being flattened out by my press.

I use a Forster coaxial loading press with an integral primer seater. It tends to flatten the primers to the same level as the base of my brass so, it turns out that my loads weren't "Over-Charged" or "Hot Loads" after all. I did find also that the .003" of additional head-space made a tremendous difference in the ease of chambering and extraction. I can now neck-size only and the brass will still chamber. This wasn't the case before adjusting the head-space. I had to Full-Length-Size in order for the brass to go into battery.

Since I adjusted the head-spacing I decided to start from scratch with my load work up. This second time out to the shooting range I started from the listed minimum powder charge and increased it by .3 grain increments all the way up to 46.2 grains of IMR 4831 powder. That's a total of 21 rounds; three of each powder charge weight; and get this, All but three of those powder charges went into one inch or slightly less at a hundred yards. That's outside to outside measurements, not center to center. Different people measure there groups in different ways, I'm taking about 7/8" outside to outside and 5/8" center to center. In my next outing to the range I'll start my loads at 46.5 grains and work my way up to max loads in .3 grain increments.

Because of the new head-space, my first three rounds were wasted. They hit about five inches low and two inches to the right. It's hard to believe that a .003" increase in head-space can cause that much POI shift. After a scope adjustment; or I should say, over adjustment, the next three shots clustered together about three inches high and two inches to the right. A final scope adjustment got me pretty close to my point of aim and from there I finished shooting the remainder of my loads.

I'll post my pics of the two targets I used just so that the claims I've just made make a little more sense.

I also wanted to mention (I hope I don't come across as arrogant or conceded here) I've been contacted by at least a half-dozen guys either through my YouTube account or through my membership here asking for some pointers on how they should go about doing their own K31s. A couple of them told me that they only joined the cast bullets forum so they could ask me a few questions about taking on such a project.

This is both flattering and frightening to me. I really didn't know anyone I could go to for advise when I did my K31, I had to just sort of wing it and hope it turned out alright. As luck or the Grace of God would have it, I ended up with a successfully completed project that many thought would be to hard or complicated to do. In spite of this, I really don't consider myself an expert in the K31 by any means.

If you're reading this and you're contemplating such a project, I have to tell you; It's Not That Hard. I know I've stated this before somewhere in this project thread; "You just have to take your time and be meticulous about every step."

HollowPoint

[Frank46]

Your build is probably the best one when it comes to the many captioned pictures and steps you did along the way to get where you are now. Besides taking on a project that many would deem extremely difficult and darn near impossible. And to the gent referring to the Precision Shooting article think it was Rocky Chandler who comissioned the K31 build in 358 winchester. And I wish I could reference the PS issue or issues that it was in. I'm still trying to find the January '03 issue that had the article for making the adapter for for mounting it on a scope block and moving the target sight back closer to the eye. Frank

[HollowPoint]

A while back I mentioned my hankering to do another such project, but this time chambering in 6.5x284 Norma. I had most of the funds well on the way to being saved up and then (as it happens in life) I lost a major filling in my mouth followed by the loss of two tires on my work truck followed by a series of bills that came due.

All of those things were taken care of but the results were that the funds I had been saving up got depleted in pretty short order so, I'm back to square one. The dream is still alive but the funds are on life support. I wish I could afford to retire right now. That would give me both the time and the resources to make these dreams come true while I can still enjoy them. That too is a dream in the making. Oh well, I guess this is what makes life interesting.

During the short span of time that this was all taking place I had been keeping an eye out for a good deal on another K31 rifle. Wouldn't you know it? In Arizona there's a website called the backpage.com where local gun owners buy and sell their guns. I came across a couple of very good deals but by then I had spent that money on dental bills, a new set of tires and insurance premiums. Such is life.

HollowPoint

[HollowPoint]

OK: Here they are. These are the pics of the two latest targets from my latest load work up.

The first one show the wasted shots I mentioned in my previous post. I didn't think that changing my head spacing by .003" would affect my point of impact as much as it did so I didn't bother to load up some "Sighter" loads. That was my mistake.

Notice the three shot cluster I got after adjusting my scope? Oddly enough; I got a similar three shot cluster when I shot my very first batch of loads. I had to do a double take and go back and look at the pics I posted of those original targets. They're not exactly the same but the fact that it happened with my second three shot string just like before seemed kind of strange to me.

No matter. This shooting session was done mainly to check for any adverse reactions to the head spacing change. What I'd really like is to get this type of groups with the full power loads. Then I think I can finess them into slightly tighter groups. After all this time passing by, it appears to have been worth the wait.

Also: I mentioned in my previous post that I'd fired a total of 21 rounds. It was actually a total of 24 rounds. It's just that I didn't count those three initial wasted rounds. Sorry about that. I suck at math.

Oh Yea; I forgot to mention, these are 100 yard groups.

HollowPoint

[gzig5]

That'll do nicely, congrats. Looks like you have a sweet spot between 45.5 and 45.8. Think I'd split that difference and run with it.

[HollowPoint]

I was thinking along those same lines. If these weren't on the lower end of the powder charge weight I'd probably do just that. I want to test the high end of the powder charge weights to see if any of those higher velocity charge weights will give me similar patterns before I fall back on the 45.5-45.8 grain charge weights though.

I don't consider my self as a velocity or speed freak when it comes to how my bullets fly. Rather, I'd like the highest velocity possible that will give me the tightest groups. I hope I'm describing that correctly.

HollowPoint

[HollowPoint]

Here's a couple more pics showing the Pre-Flattened primers I mentioned earlier. The upper row of seated primers were installed using my Forster Coaxial loading press.

I wasn't able to get the right camera angle to show just how Pre-Flattened they really were. They worked reliably enough, it's just that "Flattened Primers" are one of the main indicators of having too high of a pressure for a given cartridge. This lead to some concern on my part. As it turns out, the low power loads were just that; Low Power-Low Pressure loads.

Until I realized that I had been Pre-Flattening them myself when I seated them, I thought that something had gone haywire in my loading routine.

The other photo is a grainy image I took with my cell phone camera. I wanted you to see how she looks during my Load work up.

HollowPoint

[HollowPoint]

It's been a while since posting anything on this topic. I've been to the shooting range a few times. I'm still working up loads. Virtually every time I've gone I've gotten more than a few MOA or better groups. The problem I've encountered is that when I've gone back to confirm my Sub-MOA loads were not a fluke, I've been met with different results.

Those different results were in the form of Sub-MOA groups from powder charges that were previously giving me just Decent-Groups and Decent-Groups from the loads that had just given me Sub-MOA groups. I can tell this rifle wants to shoot and I know this rifle will do better. I've even tried shooting off of a hands-free rifle rest with a remote trigger switch just to take my self and all of my shooting imperfections out of the equation. The results have been nearly the same. You can't imagine the frustration here; or maybe you can.

A few days ago I was loading up what I hope will be the last of my loads before turning my attentions to cast lead bullets for this newly re-chambered rifle. I was loading the last of the four highest powder charges which will bring me to the listed maximum loads for the 6.5x55 Swedish Mauser cartridge. As luck would have it, one of my loaded rounds happened to tip over while I had it standing on my work bench. I caught it before it rolled off the table but I noticed as it rolled that the tip of the seated bullet was wobbling up and down like crazy. It had massive runout. All this time I'd assumed that my bullets were being seated concentrically.

By the time I found this out I had already reloaded about 40 rounds. When I did the roll-test on the other thirty-nine rounds I found that virtually everyone of them had varying amounts of runout. A light bulb went on in my head. This might very well be what's causing my groups on target to vary from just Decent to Sub-MOA when testing and re-testing the loads I've been working up. The combination of these long skinny-A$$ 6.5mm bullets in conjunction with the Lee budget reloading dies I've been using seemed to have thrown a monkey wrench into my reloading regimen.

I took all of those loaded rounds back apart and re-did them. This time when I was seating the bullets I initially seated them very shallow, then I'd spin the cartridge in the shell holder about an 1/8 of a turn, seat a little more then spin the cartridge another 1/8 of a turn more until I reached my desired overall length. It took a long time but when I Roll-Tested them again there was no longer any perceivable runout. Now I'm anxious to get to the range again to see if this runout was the culprit behind the variance in my target grouping.

I titled this post "One Last Mod" because as I get into the higher powder charges the cycling of my bolt appears to be getting ever so slightly stiffer. The bolt still cycles as it should but, I can feel just a tad more initial resistance just before the fired brass releases its grip on the walls of my chamber. With this in mind I decided to reconfigure my Charge-Handle and incorporate a flip-out lever that will act as a sort of cam at the rear of my receiver. That flip-out lever will effectively facilitate the breaking of that grip of the fired brass against the walls of the chamber and it will also mitigate the distance that factory bolt knob sticks out the right side of the receiver. From the factory, the K31's bolt handle sticks out the right side about an inch and a quarter when measured from the right face of the receiver. This reconfigured Charge-Handle will bring it in a little tighter in to the receiver.

I've already milled a mockup out of 1018 steel just as a proof of concept sort of thing and it cycles and functions as I'd hoped. Even though the Charge-Handle is not a "Load-Bearing" part (for lack of a better description) I think that 1018 steel is a bit to soft for this application so I'll be making the flat part of my Charge-Handle out of 304 stainless. The actual spring loaded lever that flips outward and retracts automatically will be made of 1018 steel; possibly even aluminum. I haven't decided on that part yet. Right now I'm just waiting on some free time to come up. My 304 stainless metal stock is already in place on my mill and the G-Code is already loaded into my mill's computer. It's just a matter of finding the time to machine the part.

It's kind of hard to picture in one's mind what I'm talking about. I'll post a few pics once I've got it done. For those of you non-purists K31 fans, I think you're going to like it.

HollowPoint

[HollowPoint]

I hate not having the free time to follow my dreams; even if my dreams are just 1-Off-Dreams.

Here are a few pics that show the reconfigured K31 Charge-Handle I mentioned in my previous post. Since reaching this stage of this project I've figured out several different ways I could have gone about this that would have improved the form and function of my custom made K31 Charge-Handle.

This means that the images here are just the latest prototypes until I get to what I really want out of this K31 mod. I'm hoping these pics are enough to give you all an idea of what I'm trying to accomplish here. Thanks for your patience.

I wish I was retired and could afford to just tinker away at will. I have a million ideas and not enough time in the day to tackle even one or two at a time. I'll keep praying for that day that I'm able to retire in good health with the financial stability to make it all happen.

In the mean time, here are those pics. The further tweaks will basically be limited to the Flip-Out Lever. All components shown here were photographed about a day after taking them from my mill. As you can see, they are still In-The-White and un-polished. I plan to both cold-blue the 1018-Steel Flip-Out Lever and then powder coat it black. The flat part of the Charge-Handle will just be polished Stainless steel.

HollowPoint

[HollowPoint]

It's still a work in progress but, I finally got the Flip-Lever I've been working on done for now. I most likely will make one last tweak to it before calling it done. I'm going to run it as it is until I can get some more free time to play around with it both in my CAD/CAM software and on my milling machine.

Here are a few more pics to give you a better idea what I'm getting at. I've tested it and it works perfectly; as far as I'm concerned. I still have yet to make it to the shooting range to test my latest batch of loads. I'll be doing that testing before I do any more tweaking to my Flip-Lever. It's just a matter of finding the time. These pics include images of my previous prototype and my latest prototype so the wording on some of the pictures may be a little confusing.


HollowPoint

[Blackwater]

HP, FWIW if anything, people today seem to have become victims of "group think," and it's nice to see someone step out into the unknown, with little more than an intention. This is the kind of spirit on which this country was built, and it'll always be valuable wherever it's found and flourishes. One never knows what they'll learn until they give it serious effort. And with a little judgment, it'll usually turn out very well to great. It's that little "judgment" thing that is always the joker in the deck. You seem to have pretty well taken care of that with all your research and measuring.

I've seen some folks do this type of thing the way you're going about it, and they always came up with good results provided they simply didn't get in a hurry and start "assuming" things before they do their due diligence. I can't wait to see your results, and read the story of your journey. It's kind'a like the journey of Ulysses. There were sirens and cyclops along his way too, but he cut them every one down to size and came out victorious. Looks to me like you'll do the same. It's so often just a matter of willingness and having the time to do it all. Pros these days have to make a living, and they do that by doing what they're familiar with. New stuff takes time to think through, and nobody wants to pay them to do all that thinking and measuring, etc, so they tend to pan such efforts. But as a way to learn guns and gunsmithing and machining, etc. it's one FINE way to do that! PO Ackley's students used to be given things to do and problems to solve as a simple opportunity to learn to think quickly, accurately and usefully. One of the things I've heard he'd do with his metal working students is to give them all a piece of scrap steel of some kind and varied shapes, and tell them to make it into a 1" cube with dead on perpendicular sides, and they had to do it all with hand tools. No machines or power tools allowed. They all hated this exercise, I'm told, but it forced them to learn to think things through and get a harmonious result, and also helped show them the real practicality of hand tools as well, when used with attention, skill and focus. Only years later did most allegedly appreciate Ackley's tougher assignments. The old man was always thinking. Even his enemies would have had to give him that!

I'll be looking for your results and the attendant story. Thanks for posting it here. I suspect all the naysayers will probably be saying "Darn! I didn't realize it could be done like that!" FWIW?

[HollowPoint]

Thanks for the kind word Blackwater:

I found that most of the "Naysayers" kind of went silent about half way through this project. I did get some negatively opinionated replies from those professing to be military surplus rifle "Purists" but, for the most part the vast majority of the folks who have taken the time to post any comments have been positive.

Some have even contacted me via email asking for pointers. It makes for kind of an awkward situation cause I'm not a qualified gunsmith or anything like that. I'm just a home tinkerer that couldn't afford to have this work done by a real gunsmith.

I figure that this K31 project will be completely finished about the time that our Arizona weather starts to cool down a bit. I'll be able to take it out in the field then; maybe coyote hunting just for the heck of it. After that I'll start looking for some cast bullet loads.

HollowPoint

[HollowPoint]

Last week I got a little free time in between jobs. It's those moments of time I spend waiting for incoming customers to show up for their appointments or waiting for those same customers to pick up their cars.

Anyway, I still had that spare K31 Charge-Handle that I had originally intended to alter to fit my dreams of a Flip-Out type of charge-handle. My original Charge-Handle was now in storage because I've been running the stainless steel one I'd made a couple of weeks back.

I decided to use this small amount of free time to go ahead and alter the spare factory Charge-Handle just to see if it could be done without any milling involved.

I removed the bolt-knobs and proceeded to cut off the part that held the bolt-knobs in place. After a little shaping to fit, I then welded that part I'd cut off, back onto the rear most part of the Charge-Handle. I never did find out exactly what type of metal was used in the making of the factory Charge-Handle so, I figured if it couldn't be effectively welded and I ruined it, it was not to great of a loss.

I'm happy to report that it took all of 20 minutes or so to complete. The weld appears to be a strong one so it should not break any time soon. No machining necessary, except for the die-grinder I used to actually cut off that part of the Charge-Handle that I welded in a different position to get what I was after. Counting the time it took me to research the metal type, research the milling of different metals and then actually milling my replacement metal of choice. I think that the stainless steel Charge-Handle I made took close to two months until I got a good usable stainless charge handle; made from scratch.

Now, in only twenty minutes I had a fully functional altered factory charge handle that required no finessing to get to work. Live and learn.

I did have to make a new Flip-Out-Lever but, this time I made the main body out of aluminum; piece of cake. The under side I made from a piece of 4140 steel I had in my junk box; and the pivoting cam-arm was made from a piece of 1/4" copper rod I had laying around. I used copper deliberately because I didn't want it to mar the reciever were it made contact as it cam'd open the bolt. And get this; this time around I used only my little Harbor-Freight mini mill to do the shaping of my Flip-Out-Lever. The remainder was done with files. I could have made the hole thing with hand files but I only had a little free time to work with.

The hardest part of making this new iteration of my Flip-Out K31 Charge-Handle was winding the little spring that would return the Flip-Handle back to its resting position against the receiver. I'm not kidding, I must have made at least two dozen attempts at getting that little spring just right before I came to the right configuration.

Anyhow, I got it done. I took several pics of my progress. I just have to edit them for posting.

One other thing; I just took delivery of my new Tikka T3 chambered in the same 6.5x55 caliber. I mention this because I needed a good scope for this new Tikka so I removed the one I had on my K31 and now my K31 is running with peep sights. I had already made a Globe-Front-Sight for it. Now I'm in the process of making an adjustable receiver mounted peep sight for the rear. I'm gearing up to start testing cast bullets out of my K31 so I want to get these new sights done for that reason.

I have an inbound Lyman bullet mold that I'll use as my cast bullet testing platform. I was able to get the 120 grain Nosler Ballistic Tip bullets consistently down to just under MOA in my 6.5x55 chambered K31. I'm hoping for the bestwith cast lead.

I'll be back after I've edited the pics I mentioned.

HollowPoint

[HollowPoint]

If this is true, the following group of seven new pics should mean that you don't have to spend to much of your valuable time reading more of my ramblings.

The home made peep sight is a bit on the bulky side compared to store bought units but, no matter. It works for me; and it was free.

HollowPoint

[samari46]

Been following your journey from the first post. I am amazed at both your photography and machining skills. Had to look twice at the rear sight and yep sure a pretty piece of work. Now all you have to do is convert your rifle to semi auto and you will be done. Kidding at the last part but fine skills. Frank

[HollowPoint]

Thanks for the kind word samari46;

I don't know about a semi-auto but I have had thoughts of making one into a pump-action. The K31 action is not to far off from a pump action shotgun's action so it's not beyond the realm of possibility.

I've mentioned before in other posts of my wanting to do another K31 project. Next time I'd attempt a 6.5x284 chambering but, every time I've managed to come close to saving up the money to do so, life tends to dump a more pressing matter on me that requires the use of those saved up funds.

I'm still waiting on my Lyman 6.5mm bullet mold to show up. It's taking longer than I'd like because I wasn't told at the time I put my money down that it was not in stock. It was on back order. I didn't want to cancel my order cause I got a good deal on it compared to the going rate for the same 150 grain mold on other websites. It should be here next week some time. Then I can see what my K31 can do with cast bullets.

I was glad to read a post from another member here. I've noticed the number of views this project thread has received to date and it makes me wonder who all these folks are. It's rare that anyone will post a comment either negative or positive. I wonder if they are guys who have thoughts of re-working their own K31's or if they're just bored so they click on this project just to see how it's coming along.

In the grand scheme of things it's not really important. I'm just glad I'm not the only one who likes this kind of stuff.

HollowPoint

[samari46]

Well you did this build right even with the do overs. excellent photos, your inclusion of captions in your thumbnail photos, easy to follow writing style and you are working on a rifle that up until about 5-6 years ago many of us had either never seen one or shot one. Everytime the big boat of happyness shows up with the swiss made GP11 gives all of us to see what these rifles can do in the accuracy department. Frank

[EDG]

No not silent. They just quit coming back.
Since you seemed to want to talk down to at commenters I think many of them decided to ignore this.


Thanks for the kind word Blackwater:

I found that most of the "Naysayers" kind of went silent about half way through this project. I did get some negatively opinionated replies from those professing to be military surplus rifle "Purists" but, for the most part the vast majority of the folks who have taken the time to post any comments have been positive.

Some have even contacted me via email asking for pointers. It makes for kind of an awkward situation cause I'm not a qualified gunsmith or anything like that. I'm just a home tinkerer that couldn't afford to have this work done by a real gunsmith.

I figure that this K31 project will be completely finished about the time that our Arizona weather starts to cool down a bit. I'll be able to take it out in the field then; maybe coyote hunting just for the heck of it. After that I'll start looking for some cast bullet loads.

HollowPoint

[Artful]

Pump gun? really?

If I were to offer any thoughts about mod's to K-31 it would be
http://img.photobucket.com/albums/0703/guisan/album%204/album%209/P3110387.jpg
http://theswissriflesdotcommessageboard.yuku.com/topic/4553/The-mysterious-Kretzonian-K31-Bullpup-Sniper#.WAhZSdQrK9I

[M-Tecs]

Pump gun? really?

If I were to offer any thoughts about mod's to K-31 it would be
http://img.photobucket.com/albums/0703/guisan/album%204/album%209/P3110387.jpg
http://theswissriflesdotcommessageboard.yuku.com/topic/4553/The-mysterious-Kretzonian-K31-Bullpup-Sniper#.WAhZSdQrK9I

Never knew about this one. Ugly but very cool

[Jniedbalski]

Great build. I also have a k31 and love it. It's one I won't get rid of any time soon. I thank the reason most don't reply it's because this project is way above what the home gun smith can do. I rember when they first imported them. They where only 69$ ffl price. I didint get one until a few years later for 200$ but I know should of bought more

[HollowPoint]

No not silent. They just quit coming back.
Since you seemed to want to talk down to at commenters I think many of them decided to ignore this.

Hi EDG:

If you were one of those who felt talked down to I hope you will accept my apology. It was never my intent to talk down to anyone.

HollowPoint

[HollowPoint]

Pump gun? really?

If I were to offer any thoughts about mod's to K-31 it would be
http://img.photobucket.com/albums/0703/guisan/album%204/album%209/P3110387.jpg
http://theswissriflesdotcommessageboard.yuku.com/topic/4553/The-mysterious-Kretzonian-K31-Bullpup-Sniper#.WAhZSdQrK9I

In the back of my mind I knew it would be possible. I actually had more of a shotgun-type of pump action in mind but this just confirms the possibility. The way I've dreamed of doing it would require the fabrication of custom stock with the linkage to cycle the action running along the side of the stock within some milled slots.

The K31 in the photo appears to be a bull-pup configuration with a secondary cocking lever up front. It looks like it weighs a ton but still, the thought that went into it is commendable.

HollowPoint

[samari46]

HollowPoint, just in case you don't know me by my handle it was Frank46 but the old computer crashed and decided to go with a new handle and password. I've now written down all the websites I go to with handles and passwords, at 70 sometimes the old brain cells don't function as well as they used too. Frank

[Jniedbalski]

For being a home hobbist and not being a gun smith or a machinist your work and pictures are first rate. Your post with pictures would make a top rate article in any gun mag .thanks for posting this article. It has inspired me to finish some of the gun projects I have going.

[HollowPoint]

For being a home hobbist and not being a gun smith or a machinist your work and pictures are first rate. Your post with pictures would make a top rate article in any gun mag .thanks for posting this article. It has inspired me to finish some of the gun projects I have going.


Thank you Jneidbalski:

Writing articles for gun mags is one of many dreams of mine that will most likely go unfulfilled. I'll eventually accomplish some of my dreams but not all of them. This K31 project is one of the small ones I guess.

If I ever get the chance to do another K31 I think I prefer a venue like this one in which to post my work. It allows for real-time feedback for my work where the gun magazines adhere to strict word count. To many details tend to get overlooked and to many readers are left scratching their heads.

HollowPoint

[Artful]

In the back of my mind I knew it would be possible. I actually had more of a shotgun-type of pump action in mind but this just confirms the possibility. The way I've dreamed of doing it would require the fabrication of custom stock with the linkage to cycle the action running along the side of the stock within some milled slots.

The K31 in the photo appears to be a bull-pup configuration with a secondary cocking lever up front. It looks like it weighs a ton but still, the thought that went into it is commendable.

HollowPoint

Yes it was a bit heavy



Some specifications of the rifle;


- K31 receiver.
- 'Furter' match-grade bull-barell, 25 inches long, free floating.
- suppressor (5 inches in front of the muzzle, 8 inches behind the muzzle, works very good).
- Overall length: 40,6 inches (that's pretty short).
- Scope Springfield 6x 40.
- Bipod is special, the rifle is 'hanging' under instead of 'standing' on the bipod.
- Special stock, build from ply-wood (in german: Schichtholz).
- Mechanical trigger connected to the original trigger in the back of the stock (bullpup-system).
- 6 round original magazine.
- This winter it got a new finish in Swiss-camo pattern, after having optimized the stock (better scope protection, as seen in the pictures).
- Weight is 16,7 pounds (a little bit heavy)
- It shoots 1 MOA, very accurately till about 800 m using original Swiss GP11 ammunition (at 800 m on a steel plate (30 x 40 cm) some 70 % hits).

[HollowPoint]

I'm a member over on the Swiss Rifle forum and I don't remember ever seeing this one either. Of course, I wasn't really looking for anything like this since joining there. It's gratifying to know that there are others doing stuff like this too.

There is something I would like to know with certainty about the K31 receiver. That is, what cartridge or chambering would represent the maximum pressures that the K31 action could repeatedly and safely withstand. No one I've spoken to seems to know for sure. This is one of the main reasons I joined that Swiss Rifle forum. There are some very knowledgable folks there but there knowledge base stems from book and magazine reading and not really from hands on knowledge.

For me knowledge of any kind, no matter how it's gained is benefitial regarding working on K31's but I've yet to come across this and other bits of information about the receiver or action components of this rifle.

I've done some informal research into it and the best I could come up with were some of the other listed chambering-s that other more recognized names have re-chambered the K31's action to. By comparing the maximum average pressures of those cartridges it gave me some idea but it was not really definitive.

HollowPoint

[samari46]

Google Larry Racine, he rebarrels K31's to 308 and makes match rifles out of them. Has a website so maybe you could contact him and see what he has to say. Frank

[HollowPoint]

I've corresponded with Larry Racine on more than one occasion about this very subject. He was very helpful and he never failed to reply to my inquiries. There are other outfits in the world like Hammereli rifle who have rebarreled K31s up to magnum calibers too but what I was really looking for was the safety limits of K31's action.

Someone is bound to have this information. Finding that someone with that particular knowledge is turning out to be very illusive. At any rate, the 6.5x284 Norma chambering that I've dreamt of will have to wait until I win the lottery or until some long lost wealthy relative passes on and leaves me enough money to undertake such another K31 project.

HollowPoint

[M-Tecs]

http://www.lprgunsmith.com/K31_rifles.htm

[2700fps]

What is the latest on this project.

I am in the middle of trying to get the blue prints so the step files can be written and attempt to get a barrel reproduced with out the adapter.
Was told on another forum about this thread. Very very informative.

If anyone has more information please chime in.