Re-Barreling/Re-Chambering my K31 Swiss

[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