I got a m44 with all matching #. The extractor will not ride over the cartridge rim. I tried using a flat blade screwdriver to loosen the tension on the extractor with no help. There was a ridge on the extractor lip. I used emery paper to smooth the ridge. Anything else I should try?
Gunsmithing Mosin nagant extractor issues.
- Thread starter Jscb1b
- Start date
Seen this issue before.
Is this a "new to you" rifle, or is it a new problem on a rifle that had been feeding/ejecting properly?
Check the depth of the boltface from the bolthead rim.
On rare occasions, this dimension is smaller than the thickness of the cartridge rim- if that is the case, you'd need to swap out the bolthead.
Changing the bolthead can change your headspace- have you confirmed headspace is correct, with either a "coin" gauge or quick and dirty by adding tape to the back of a dummy round or sized brass?
Do this with the fp spring removed from the bolt.
If you're able to confirm my suspicion, I have a box of boltheads...
If your headspace is correct, I'd need a measurement from back of lugs to boltface and I can send you one that'll match up.
I've swapped them out before, to gain or tighten headspace a few thousandths either direction.
Is this a "new to you" rifle, or is it a new problem on a rifle that had been feeding/ejecting properly?
Check the depth of the boltface from the bolthead rim.
On rare occasions, this dimension is smaller than the thickness of the cartridge rim- if that is the case, you'd need to swap out the bolthead.
Changing the bolthead can change your headspace- have you confirmed headspace is correct, with either a "coin" gauge or quick and dirty by adding tape to the back of a dummy round or sized brass?
Do this with the fp spring removed from the bolt.
If you're able to confirm my suspicion, I have a box of boltheads...
If your headspace is correct, I'd need a measurement from back of lugs to boltface and I can send you one that'll match up.
I've swapped them out before, to gain or tighten headspace a few thousandths either direction.
It is a new to me rifle. It was found in a barn 10 years ago. The guy I got it from said he never tried to shoot it. I don't have a coin gauge so what is the trick with the tape? If the tape wipes off is the head space to tight? If it doesn't wipe off is the headspace to loose? I can remove the bolt, slip a cartridge under the extractor and then the round will chamber.
If the extractor snaps easily over the rim and chambers, sound more like it might be excessive headspace- round is able to be pushed further forward than should be, so the extractor can't grab the rim.
Take some cellophane package tape, cut a small piece and stick it over the end of the dummy round or sized case (recommend not doing this with a live round- but if you must do it safely). Trim the tape all around the case with a new razor blade. Do it again, for a second layer.
Disassemble the bolt. Youll need to either notch the rim of a sized empty case so the extractor doesnt interfere, or remove the extractor which can get a bit hairy since you dont have the coin gauge with a notch in it. The extractors will bend, and somerimes snap if youre not careful. if you remove it, bend back slightly and pit a few drops of kroil in there before trying to drive it down and out- it's a dovetail fit. Slip the round by hand into the chamber, then slide the bolt into the receiver, push all the way forward and gently begin to lower the bolt handle. If you can put it into battery without resistance, add another layer of tape, and repeat. If it still closes, you've probably got excessive headspace...
Each layer of tape is .003-.004 thick on average, closing on even two layers is questionable and three would be indicative of the problem.
This can happen from lug setback- but also from a "mixmaster" rifle where someone has swapped the bolthead without checking headspace after. Just like a Savage, these rifles have floating boltheads (which allows these receivers to be built into pretty accurate rifles for those that wish to do so) and dimensions vary by as much as 6 thou or more.
Hope this helps...
Take some cellophane package tape, cut a small piece and stick it over the end of the dummy round or sized case (recommend not doing this with a live round- but if you must do it safely). Trim the tape all around the case with a new razor blade. Do it again, for a second layer.
Disassemble the bolt. Youll need to either notch the rim of a sized empty case so the extractor doesnt interfere, or remove the extractor which can get a bit hairy since you dont have the coin gauge with a notch in it. The extractors will bend, and somerimes snap if youre not careful. if you remove it, bend back slightly and pit a few drops of kroil in there before trying to drive it down and out- it's a dovetail fit. Slip the round by hand into the chamber, then slide the bolt into the receiver, push all the way forward and gently begin to lower the bolt handle. If you can put it into battery without resistance, add another layer of tape, and repeat. If it still closes, you've probably got excessive headspace...
Each layer of tape is .003-.004 thick on average, closing on even two layers is questionable and three would be indicative of the problem.
This can happen from lug setback- but also from a "mixmaster" rifle where someone has swapped the bolthead without checking headspace after. Just like a Savage, these rifles have floating boltheads (which allows these receivers to be built into pretty accurate rifles for those that wish to do so) and dimensions vary by as much as 6 thou or more.
Hope this helps...
I pulled the bullet from a live round then popped the primer. I then filed away the rim about 1/2 way around the case. When I drop the case in and try to close the bolt it does not close. When I tried another case that was snapped under the extractor and then closed brass shavings came off the face of the case. Could this be not enough head space?
Conflicting information...
You stated initially that rounds would chamber.
If headspace were short (barrel breech to boltface for the rimmed round) you would not have been able to chamber/get the bolt fully into battery.
You stated initially that rounds would chamber.
If headspace were short (barrel breech to boltface for the rimmed round) you would not have been able to chamber/get the bolt fully into battery.
Bingo, excessive headspace. Too much clearance between boltface and the breech of the barrel, the "slop" won't allow the extractor to be forced over the rim.
If the bolt isnt numbers matching to the receiver, someone probably just threw a different bolt into it. The Okie ground headspace gauges i use in the shop arent made anymore, but i believe another company (Firewerks, maybe) makes similar, which would be the correct and accurate way of confirming your headspace...but the tape is a reasonably accurate indicator.
If you like...
Carefully remove the extractor as described above, and you can slip calipers under the back of the bolt lug and over the boltface to get that measurement.
PM me and Ill go into the pile to see if I can find one that you can swap out to decrease the headspace clearance. Theres no way to check lug setback without pulling the barrel; Ive seen a few thousandths before but never that much so I suspect the mismatched bolthead.
If the bolt isnt numbers matching to the receiver, someone probably just threw a different bolt into it. The Okie ground headspace gauges i use in the shop arent made anymore, but i believe another company (Firewerks, maybe) makes similar, which would be the correct and accurate way of confirming your headspace...but the tape is a reasonably accurate indicator.
If you like...
Carefully remove the extractor as described above, and you can slip calipers under the back of the bolt lug and over the boltface to get that measurement.
PM me and Ill go into the pile to see if I can find one that you can swap out to decrease the headspace clearance. Theres no way to check lug setback without pulling the barrel; Ive seen a few thousandths before but never that much so I suspect the mismatched bolthead.
