The problem of 91/30's was well known in the '70's through the '90's. Many bring back rifles from Vietnam ( I had a couple) had rough bores. In the middle eighties thru the '90's some unscrupulous wholesale houses were vat cleaning MN's to make them look better, cutting them down, threading the barrel and selling them as shooters.
This wasn't a problem until the Chech ammunition started to be imported. Chech ammo had a heavy coat of lacquer which preserved them very well. When you combined them with rough chambers, it was an accident waiting to happen. This stuff was so bad, if you shot a 20 round box one after another in a pristine chamber, it would still start sticking as the rifle heated up.
When this happens, usually you will rip the rim off trying to get it out with the bolt. The next thing some people did was unknowingly allow the bolt to go back over the magazine interrupter. Then they would ram the bolt home not noticing that it had picked up another round.
I have seen two people injured in this manner. One has a scar on his underarm with about 100 stitches in it. The other had less damage but it was across his hand and cut some nerves. In both cases, the round acting as firing pin did not detonate. The gas coming out of the receiver is what did them in as the bullet plugged the barrel and the gas took the path of least resistance. The case of the one I saw was split lengthwise and didn't appear to have fragmented at all. The bolts stayed in both guns and they probably would have functioned again after cleaning.
This risk has been mitigated by the surplus market drying up. Just remember if you buy surplus 7.62x54 ammo and it comes in a green or blue box of twenty, it will be lacquer coated. Those of you shooting PP or even Russian surplus, shouldn't have any problems.
Single feeding will not stop this from happening. And what happened is not specific to Mosins. Any rifle that does not extract a live round could have this happen.
Generally when bench shooting I single load.
Even with semi auto rifles.
If there’s an ammo / rifle problem I can rapidly detect what’s going on, malfunction cause, clear the breech, Examine brass etc then carry on.
I already know the magazine works, extraction occurs as expected and everything is going as planned.
After the shot is plotted I can then inspect brass, make sight corrections log info and all that happy horse&$”t.
I don't own a Mosin...
Controlled feed FTW.
By design a controlled feed rifle is less likely to have a double feed issue. Unless the extractor claw is broken off. From the moment the bolt is moving forward to strip a round from the magazine, as the cartridge is coming up it gets hooked by the extractor. On a push feed rifle (like the mosin) the extractor does not lock onto the case rim until the bolt is fully seated/closed.
That sounds miserable.
Double feed? No matter how I try to think, I cannot picture how. Sound like the cartridge fired before chamber. Might be firing pin protrusion problem.
Round was stuck in the chamber. Shooter pulls hard on the bolt and breaks the rim of the case off, then rams the bolt back without thinking about it picking up a round from the magazine.
No. Actually what has happened in the cases I have seen, the rough chamber was cruded up by Lacquer, carbon and unburned powder. The next round does not fully chamber but sticks, the shooter beats the bolt open and, suspecting the extractor has just "come off" the rim, rams the bolt back to try to remove it. When the bolt comes back far enough it rides over the interrupter and allows a round to come up ready to chamber. When the bolt is thrown forward, the new cartridge hits the primer on the stuck cartridge and it explodes. The bullet goes forward and blocks the barrel and the gas heads backwards. Since the bolt is not locked, the pressure pushes on the case which sends the bolt back as the case ruptures. BTW, the one I saw, just opened up and did not fragment. It happened just like the demos I saw during EOD training in the military. That hot gas coming out is what tears up the shooter.
No. Actually what has happened in the cases I have seen, the rough chamber was cruded up by Lacquer, carbon and unburned powder. The next round does not fully chamber but sticks, the shooter beats the bolt open and, suspecting the extractor has just "come off" the rim, rams the bolt back to try to remove it. When the bolt comes back far enough it rides over the interrupter and allows a round to come up ready to chamber. When the bolt is thrown forward, the new cartridge hits the primer on the stuck cartridge and it explodes. The bullet goes forward and blocks the barrel and the gas heads backwards. Since the bolt is not locked, the pressure pushes on the case which sends the bolt back as the case ruptures. BTW, the one I saw, just opened up and did not fragment. It happened just like the demos I saw during EOD training in the military. That hot gas coming out is what tears up the shooter.
Cresap RSO will enforce a similar cadence. Why would you call HB anti gun?
In case you don't know, the MN44 was zeroed with the bayonet extended. Additionally, I have made many MN's shoot well by cutting an inch off the barrel and recrowning it. Sometimes it didn't take that much and I didn't have to reloate the sight.