I need a little advice from anyone in my Monkey family...I have a mosin-nagant rifle that the bolt will "lock up" on after I fire about 7 or 8 rounds ...the rifle and bolt are clean and well lubricated and the ammo is soviet military issue...the empty shell casing do not appear to be swollen or damaged in any way...anyone have any ideas?
That is perfectly normal with Russian M-Ns. I haven't the least clue why it happens, but it does. Have a look at 7.62x54r.net, there might be something new added since I last looked.
I had that problem with Czech light ball ammo in my M44. I first switched to the copper-washed Hungarian heavy ball - much better, as the Czech is lacquered, The lacquer gets into the chamber and bolt lug recesses. Next, I used a cleaning rod with .410/.45 bronze brush, a bit of steel wool on it, then some good bore solvent - spun it slowly in a variable drill, and cleaned the chamber really well. DON'T go into the bore! Use a good set of small bruches, pics, Q-tips, whatever works to get the lug recesses clean. Often some old dried Cosmoline is in there too. I have also begun handloading my 7.62X54R ammo using good commercial brass cases. Pretty much solved the problem!
Mosin-Nagant I had bought a couple of the m-91's one shot perfect and the other one done what you are talking about so I took it to the local gun shop because I couln't figure it out. He told me that when these guns were sent to the U.S. that alot of them came in boxes and that when they put the guns together to be sold if one had a worn bolt or other part they would pull another bolt from the box. He said that when the guns were produced the bolts was hand fitted to each gun. With them just switching the bolts its was causing some problems with the bolts locking up. He said the bolts wasn't seating properly in the chambers when they changed them out. Which seemed to be a good reason to me because one I had the numbers on the bolt matched the numbers on the gun it shoots like a champ. I checked the other and the numbers didnt match. I also had the same thing with my first M-44 then I lucked up and found one in perfect condition all matching numbers.
Both of mine (91/38 and an M44) have matching numbers, and both get a mite "stiff" after 5 or 6 of Bulgie 182 gr milsurp. Cool off, and they loosen up.
I know it's not from the extremely close tolerances! I had a few problems with my M-N's with those danged lacquered rounds... They gum up the works if the chamber and bolt get a bit warm.... But most of that was evident in the SKS rifles....more so than the M-N's. I do know you have to watch out for those serial numbers, as I had a gorgeous 98K that was a real monster as it was "piece meal" assembled. Never would function correctly!
I had this issue ^. The lacquered cases with an arsenal refinished 91/30 made extraction tough. I polished out the chamber and changed ammo- problem solved. Its quite common.
