School me up on the K31

[Gutter]

Take a look at the other thread I posted about bringing home my K31. I was told that Howard Feed'N'Wax would do the trick and it did. The one I got is great, but the stock has a lot of "character" if you will. I hit it with some Murphy's to clean the surface grime off and then used the wax on it. It took out all the grime that could be removed sans heavy scrubbing, brought out the grain, and moisturized the wood. Preserved everything and cleaned it up a little bit.

[Guisan]

Ok. Sorry to hijack my Son's name and password, but he directed me to this one. Little time available for me right now so I'll make it short.
Guisan is right about that possibility. We've done this on a very large number of rifles as have many many other SRDC members without that happening. Can it happen? Of course. They're very old rifles, and metals can crystallize with time. Every rifle in the armoury has had this process performed, and the accuracy immediately improved. Two schools of thought. Drop the stock and look at the contact point.
Your rifle.... your decision.

P

P.
It's simple in fact, take off both barrel bands and remove the hand guard, check if both screws are dead tight and simply fold a dollar bill under the barrel and pass it all the way through till the front sight.
When that gives no complications you are ready for step two which is the upper handguard space but that is another story....

[kouye]

P.
It's simple in fact, take off both barrel bands and remove the hand guard, check if both screws are dead tight and simply fold a dollar bill under the barrel and pass it all the way through till the front sight.
When that gives no complications you are ready for step two which is the upper handguard space but that is another story....

I've already done this and do not have any contact points under the barrel to the muzzle. That's when I noticed a tiny gap under the muzzle so I put the 0.005" shim under the tang and the gap (I have since removed the tang shim). The alternative would be to put a thinner shim at the action screw.

As for the handguard, I guess I can shoot it w/o the handguard and see what happens. If the groups were tighter, then I'd shim the handguard rails, shim the barrel band screws, and reinstall.

[Gutter]

I was cleaning and reassembling the bolt for the first time yesterday and I noticed that the bolt seemed a little stiff/sticky when first being cocked. Is the K31 supposed to feel this way? I've only ever shot a few rounds out of a friend's 91/30, which was a bit smoother, and I'm assuming this is typical as this is compressing the spring on the pin (if I'm correct). Doing so again a second and third time yields no issues and is pretty smooth. The bolt is sufficiently lubed, but I want to make sure this is not a reassembly issue on my part. I think it's just me being a concerned father over a new gun, but I wanted to double check before I take it out and ruin something.

[Guisan]

I've already done this and do not have any contact points under the barrel to the muzzle. That's when I noticed a tiny gap under the muzzle so I put the 0.005" shim under the tang and the gap (I have since removed the tang shim). The alternative would be to put a thinner shim at the action screw.

As for the handguard, I guess I can shoot it w/o the handguard and see what happens. If the groups were tighter, then I'd shim the handguard rails, shim the barrel band screws, and reinstall.

That's the wrong way, the handguard has a task also, compare it with a garden hose, when you hold that one some 8 inches from the end loosely the water goes everywhere, now hold it that same way some 2 inches from the muzzle and see what happens....

[kouye]

That's the wrong way, the handguard has a task also, compare it with a garden hose, when you hold that one some 8 inches from the end loosely the water goes everywhere, now hold it that same way some 2 inches from the muzzle and see what happens....

Right, but I had already tried shimming the hand guard at the muzzle with a thin piece of cork on top of the barrel and the groups got bigger. However, I may have overtightened the front band.

I ended up trying the loosened (3/4 turn) tang screw and the group (5 shot) got tighter. As I tightened it (1/8 turn at a time), the groups got marginally larger. I'll admit that I don't really like the idea of the rear screw being loose, but it did seem to help.

I'm going to experiment with various thickness of shims under the action bolt and/or under the tang, as well as a shim at the muzzle to keep the front of the handguard a little tighter.

[Guisan]

Shims in the front band can help but that is not the solution to the real problem.
The gap between the barrel and the opening where it leaves the wood should be tight all around so only little more as that dollar bill I mentioned and not more or it looses it's support function.
It is also the reason why sporterized K31's with the stock cut short loose their accuracy.

When a shot is fired the barrel end makes a swing, a screw-on damper can reduce that but it is actually the task of the stock and the handguard.

Putting a shim under the tang changes the angle of the triggerhousing against the wood buffer in the stock to the left and instead of fully against it only the lower part of the housing is and this can result in a cracked stock in the lower wrist of a cracked trigger assembly housing in the rear top section.



Sorry for the text, I'm posting at forums in other countries like for example Switzerland also, the left arrow is pointing to the spot where it cracks when you play with the tang screw, the recoil forces should be spread over the complete vertical section and not on just the lower part of it.
In this drawing you can also see the shims inside the stock where the front action screw goes through.

[kouye]

Thanks for the info. Guisan!

Without a shim under the tang, when the screws are tightened down, the gap under the barrel at the muzzle was a bit more than needed for a dollar bill to slide under it. That's why I added the 0.005" shim under the tang and the gap was closed a bit. My theory was that the wood had been compressed at the tang due to overtightening of the tang screw over an extended period of time.

What I'd like to try is putting a thinner shim at the front action screw, however, the thick metal shim there appears to be embedded into the wood as it won't come out without some amount of force. Is there an easy way to remove it?

I also wanted to try shooting without a handguard in case it was touching somewhere other than at the muzzle. I had this happen with an M39 recently and it made a world of difference to sand down the high spot and only have it touch at the muzzle.

[Guisan]

Stick a screwdriver blade through the hole under the shims to let these pop up to get the whole package out, take the most tin one out of the package and measure again.

[kouye]

There's only one think plate/shim that I can see, unless there's one under it.

Edit: Okay, so I replaced the action screw shim with one that is slightly thinner. I can now run a dollar bill under the barrel from the front edge of the rear sight to the front sight. I have the rear band only tight enough to keep it from slipping over the retaining spring. The front band is cinched down to about 5 in/lb.

[OpenSightsOnly]

Question on the 1.5 - 2 plus flyer . . .

What ammo are you using? GP11 or reloads?

I'm just trying to get a baseline on my rifles at 100 yards before extending them. At this point all 4 M39's shooting Russian Match ammo will outshoot my K31 with GP-11 or any commercial ammo I've tried (Hornaday SST, A-MAX, and BTSP, and PPU). I shoot from a bench with a scope to take the shooter out of the equation when testing rifles. The M39's generally shoot 1-1.5MOA with the match ammo and the K31 will shoot 1.5-2MOA but usually I get a flyer in a 5-shot group.

I was wondering how my K31 compares to other K31's in general to see if my rifle needs some work or not.

[kouye]

Question on the 1.5 - 2 plus flyer . . .

What ammo are you using? GP11 or reloads?

GP11 for now, but I've tried PPU Match and Hornaday 168gr A-Max with similar results.