New Bolt Head

[entropy]

If it is not a headspace issue, you shouldn't need to change the bolt head. I'd check into whether the extractor is functioning correctly first, then clean it for sticky bolt syndrome, (See the tutorial on this site for that), and check the chamber for burrs befor starting the stick bolt fix. Putting a new bolt head in will fix it if it is the extractor, and since you already have the bolt head on it's way, sure can't hurt to try it. If it still does it after switching the bolt head, you can be pretty sure it's sticky bolt syndrome. Don't forget to check the headspace after changing the bolt head. HTH.

[Kristie]

I've had the extractor out twice trying to bend it so it can definitely catch the rim. And I've used sandpaper on all the edges, too. If there's a burr in the chamber, then what? Seems like when I started my original thread on the problem, no one thought it was sticky bolt syndrome. But I'll consider it again. Yep, I hope I remember to check the headspace again, because I know I'll want to go out and shoot some test rounds as soon as I get the new part in.

[Junk Yard Dog]

99% of the time it is just sticky bolt, a problem that can sometimes amaze people not familiar with steel case ammo and these rifles.

[WeldonHunter]

I've had the extractor out twice trying to bend it so it can definitely catch the rim. And I've used sandpaper on all the edges, too. If there's a burr in the chamber, then what? Seems like when I started my original thread on the problem, no one thought it was sticky bolt syndrome. But I'll consider it again. Yep, I hope I remember to check the headspace again, because I know I'll want to go out and shoot some test rounds as soon as I get the new part in.

In the future when you have a problem and go through certain steps to address it you might want to repost in the original thread when you decide to do something. The problem with starting a new thread about an ongoing problem that was already posted is all the suggestions and things you've tried are unknown the anyone new coming in to the thread so they're going to suggest things to do that have already been suggested and you've tried already. Even guys that suggested things in the original thread might not remember the history of your original problem. Don't hold that against us, a lot of us are getting old, lol. Here's the original thread. viewtopic.php?f=5&t=16125&p=254364#p254364

[Kristie]

I've had the extractor out twice trying to bend it so it can definitely catch the rim. And I've used sandpaper on all the edges, too. If there's a burr in the chamber, then what? Seems like when I started my original thread on the problem, no one thought it was sticky bolt syndrome. But I'll consider it again. Yep, I hope I remember to check the headspace again, because I know I'll want to go out and shoot some test rounds as soon as I get the new part in.

In the future when you have a problem and go through certain steps to address it you might want to repost in the original thread when you decide to do something. The problem with starting a new thread about an ongoing problem that was already posted is all the suggestions and things you've tried are unknown the anyone new coming in to the thread so they're going to suggest things to do that have already been suggested and you've tried already. Even guys that suggested things in the original thread might not remember the history of your original problem. Don't hold that against us, a lot of us are getting old, lol. Here's the original thread. viewtopic.php?f=5&t=16125&p=254364#p254364[/quote

Well, I would've done that if I had started the thread with the purpose of more troubleshooting in mind, but my only intention was to skip all that and just get some advice on where to get a new bolt head.

[Junk Yard Dog]

Ebay, gunbroker if Liberty tree is out. You may have to buy an entire bolt to get the head, but unlikely. Option is also to buy another Mosin, swap boltheads with the rifle you have and likely both will then pass.

[Kristie]

Okay, got the new bolt, put it in, aaaaaaand it doesn't work any better. It might be worse. I have problems opening the bolt now, too, instead of just closing. The only difference I can see between this new bolt head and the old one is the extractor on the new one doesn't stick out quite as high. Must not matter, though. Oh, and the recessed rim on the inside is wider, which also must not matter. Took the extractor out of the new one because I could see there was gunk under there. Cleaning it out didn't help either. Both of them don't close on the no-go gauge. I'm really, really frustrated at this point.

[Junk Yard Dog]

It's very rare that a bolt head swap will not help, you could try another bolt head or an entire bolt body swap. There are three parts on the bolt that will effect headspace if changed, the head, transfer bar, and the body itself. I had six Mosins that failed to pass the no/go, three refurbs, a M91, and two Balkan 91/30's, all were fixed with a bolt head swap, in one case I simply swapped bolt heads between two of the failed rifles and both then passed.

[Kristie]

I guess this is turning into another troubleshooting discussion after all! I started thinking maybe there was something to the idea that it's just a sticky bolt issue. So I started researching all the techniques for dealing with that. But now I'm noticing that people who complain of this issue have problems opening the bolt, not closing it. And this makes me think that this can't be my problem at all. I'll still probably give polishing a go, even though I can't see anything in there that might be causing a problem. In any case, just for kicks, I'm going to put up an image of the inside of the chamber, hoping anyone can spot anything that might be off, maybe even with the machining.

[Junk Yard Dog]

Am I looking at a crack in the chamber rim, or is it just the pic??

[Junk Yard Dog]

Sticky bolt is an extraction issue, it has nothing to do with headspace

[Kristie]

Am I looking at a crack in the chamber rim, or is it just the pic??

On the far right? I think it's just the way the light is.

[InOmaha]

The machining on the edge area the extractor slides in looks rough. It could be hanging up there. You can mark the metal surfaces and look at them after you try to work the bolt. It's probably a matter of a sharp side of the extractor catching one of the milling marks. If you can get it to work normal wear would make it better over time.

But that's a guess without being there in person. Maybe grease the edge of the chamber around where the extractor goes and see if you can get the bolt to work. Then look for clean metal to give you and indication of a rub point. You don't want to take anything off the chamber or bolt head that you don't have to.

Another option is to remove the extractor and try the bolt head with a spent casing (you'll have to remove the casing some other way). If everything functions, you've narrowed it down to the chamber surfaces around the extractor.

[Junk Yard Dog]

The problem is not extraction, the rifle has failed to pass headspace using the No/Go headspace gauge twice. He has swapped the bolt head and the rifles is still a fail.

[WeldonHunter]

The machining on the edge area the extractor slides in looks rough. It could be hanging up there. You can mark the metal surfaces and look at them after you try to work the bolt. It's probably a matter of a sharp side of the extractor catching one of the milling marks. If you can get it to work normal wear would make it better over time.

But that's a guess without being there in person. Maybe grease the edge of the chamber around where the extractor goes and see if you can get the bolt to work. Then look for clean metal to give you and indication of a rub point. You don't want to take anything off the chamber or bolt head that you don't have to.

Another option is to remove the extractor and try the bolt head with a spent casing (you'll have to remove the casing some other way). If everything functions, you've narrowed it down to the chamber surfaces around the extractor.

Removing the extractor and trying it is a good start. It's a process of elimination but I wouldn't use a spent round. The tend to be expanded and don't like to chamber. There's a possibility you have something in the chamber too. Even though you've cleaned the chamber there may be something stuck in there that still didn't come out. We had a user that had a similar problem and it turned out to be a small piece of shell stuck to the chamber wall. He couldn't see it though. You may also try just putting a round in the chamber and seeing if it seats properly without using the bolt. The rim of the round should sit tight to the chamber face. If you can get a round to sit in the chamber fairly easily this might help in the elimination process.

[Junk Yard Dog]

Mike, the problem is that his rifle has failed it's headspace check twice. Any extraction issues it may have are immaterial if he can't shoot it at all anyway. He has swapped bolt heads and it's still a fail.

[WeldonHunter]

Mike, the problem is that his rifle has failed it's headspace check twice. Any extraction issues it may have are immaterial if he can't shoot it at all anyway. He has swapped bolt heads and it's still a fail.

In the post above he said both bolt heads don't close on the no-go gauge. That's a pass isn't it?

Okay, got the new bolt, put it in, aaaaaaand it doesn't work any better. It might be worse. I have problems opening the bolt now, too, instead of just closing. The only difference I can see between this new bolt head and the old one is the extractor on the new one doesn't stick out quite as high. Must not matter, though. Oh, and the recessed rim on the inside is wider, which also must not matter. Took the extractor out of the new one because I could see there was gunk under there. Cleaning it out didn't help either. Both of them don't close on the no-go gauge. I'm really, really frustrated at this point.

In his original thread he said that was one thing he checked. I think his problem has been chambering rounds. viewtopic.php?f=5&t=16125&p=254364#p254364

[Kristie]

The problem is not extraction, the rifle has failed to pass headspace using the No/Go headspace gauge twice. He has swapped the bolt head and the rifles is still a fail.

Wait, it's not supposed to close on the no-go, so it's passed with both bolt heads, right?

EDIT: Weldon, you beat me to it, and I'm glad you brought up the old thread for me, which I needed after all. Yes, the problem is getting the bolt to close on most rounds, not all. Sorry for all the confusion. I feel like I'm being an immense problem, here. I wish the problem would go away, so I can, too!

[Kristie]

I'll try a live round in the chamber face without using the bolt when I get home.

[WeldonHunter]

The problem is not extraction, the rifle has failed to pass headspace using the No/Go headspace gauge twice. He has swapped the bolt head and the rifles is still a fail.

Wait, it's not supposed to close on the no-go, so it's passed with both bolt heads, right?

EDIT: Weldon, you beat me to it, and I'm glad you brought up the old thread for me, which I needed after all. Yes, the problem is getting the bolt to close on most rounds, not all. Sorry for all the confusion. I feel like I'm being an immense problem, here. I wish the problem would go away, so I can, too!

Correct it's not supposed to close on the field or no-go. The go gauge is the one it should fully close on. The go gauge measures minimum headspace and the others field and no-go are for measuring to see if you have to much headspace. The field guage is for just as it's name suggests for measuring in the field and is more forgiving then the no-go which is checking for a tighter clearance. If a rifle fails the no-go but passes the field it's still safe to shoot but indicates the rilfe is getting close to maximum acceptable clearance. This is from Todd's site at Okie Headspace Gauges. It's down the page here under "Directions For Use". http://www.okiegauges.com/

"For the GO gauge the bolt should FULLY CLOSE with minimal pressure to pass.
For the NO-GO or FIELD the bolt SHOULD NOT fully close with minimal pressure to pass."


You're not being a problem either. This is one of the things we do here. Help people figure out problems. It's just a bit hard without having the firearm in our hands.