Just finished putting together my Romanian SKS. Well I thought I had because when I went to put it together I discovered my headspace no go gauge slipped right in. Unfortunate but that doesn’t mean it’s unsafe to shoot necessarily. So I checked with my feeler gauges keeping this thread in mind https://sks-files.com/index.php?topic=5463.0 (TLDR 0.004-0.008 being acceptable). It was 0.011 out. That’s a bit much. So my question is what now? I’ve heard of Romanian bolt assemblies being slightly different than other countries so am I SOL or could I just have gotten unlucky with my bolt. I’d REALLY like to avoid pulling the barrel and doing work to this rifle’s headspace that way. Suggests welcome.
(https://i.ibb.co/qLQkM8qC/IMG-6716.jpg) (https://ibb.co/spYyv4xC)
As far as I know the bolts are pretty much interchangeable between countries. The main difference is the early Russian spring loaded pin bolts. You might try another Chinese bolt or maybe a Yugo bolt. Otherwise, a fix on the existing bolt is to weld a bead on the lower angled rear portion of the bolt then re-fit/machine it to recover head-spacing. it will need to get re-tempered when you do it though as it would be brittle otherwise.
EDIT to add; You also need to be sure to maintain the degree of angle when you re-machine/fit it after the weld.
Ok so I’ve given it some thought. My solution is as follows.
1. Pull the barrel
2. Source a barrel that is under clocked (meaning instead of a 16 index mark I get an 8-12)
3. Carefully remove material from the receiver face until the barrel is properly indexed
4. Use a chamber reamer to correct the hopefully too tight headspace.
I don’t have a lathe so this is the best solution I can think of at the moment. Different barrel but I’d rather have a functioning rifle
That is a ton more work than what I suggested, which has been a proven method over the years. Cheaper and easier even if you pay a machinist to do it. You are just adding .003-.005" on that angled area and refinishing it.
I’m not comfortable with the idea of welding the bolt body and re tempering it. I’ve got no idea what material it’s made out of for when I do the heat treatment, and idk how to compensate for the new material that would be added when doing the treatment. And frankly I don’t entirely trust most people to do that level of work. And those I do are very expensive. If I had a better metallurgical understanding I’d do it but I don’t.
I’m not welding it. I’d rather do all that work as outlined because I understand that and know how to do that. Not saying you are wrong, just that I don’t know enough to do so safely or ensure it was done safely.
Go through some other bolts before messing with heat and wrenches. That's what I do when building around a barreled action. I've got s brand new TAPCO bolt (would need to be fitted) or half a dozen Chinamen I'd let you try to fit. Pay for shipping both ways, find one that works, buy it with yours as a core. Some are stripped, some are ground for mag drop, some are complete. PM if interested and I'll dig around and see what's left, send you a pict. PAX
I agree with PAX, try another bolt or two from another SKS you already own just to see if you can get that number down in the single thousandths. If so, maybe source a new bolt before you tear into things.
What you propose would certainly work, but man that's quite a bit of work to gain 3 thousandths. I wonder if the square locking lug key stock on the receiver is worn? If so, maybe it could be reworked or replaced to get you there? I'm not sure the size, I'd be surprised if it's not a std. metric key though. If standard you could get a length of 4140 keystock (likely oversized), cut to length, chamfer the leading edges and press it in place to have a drop in replacement. If non-standard, you could pretty easily get any mom and pop shop with a bridgeport to mill you something out of a hardened steel that will be a nice light press fit to get there.
I’ll try swapping in a pile of my other SKS bolts to see if any of them are close. It’s definitely more work but I’m happy to take the hard road to build up my own skills. Finally got a barrel vice so the pipe wrenches can stay in the box lol. If it looks to be bolt specific I’ll definitely take you up on that