Re-Barreling/Re-Chambering my K31 Swiss

[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

[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 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?