Signs of high pressure in a Mosin m44.....

[W Turner]

I have had this rifle for about two years and have shot various surplus thru it with no issues. The last time I took it out I was shooting S&B's 200 gr SP load thru it trying to get it sighted in with the new Mojo sight. I policed up my brass when done and didn't give it a second thought until the other day.

I was cleaning out my closet when I came across the pieces of brass that I had shot that day. I happened to take a good look at them and noticed definite cratering around the primers. All of them were uniform, but there were not other signs. I remember the bolt being a little sticky after each round, but had not attached any significance to that until now. The accuracy was dreadful as well, but I attributed it to the fact that I had a brain fart and forgot to extend the bayonet when shooting. Recoil was stout, but not any worse than any other time I have shot it.

Is it possible that this particular lot of ammo is loaded a little hotter than usual? Is there anything that could be wrong with the rifle that could be causing the high pressure? I have shot other ammo before with no issues that I can recall. I also noticed that the brass was bright and shiny around the rim and casehead, but has a slightly "frosted" look where it would have been chambered. Is this indicative of a possible problem?

Any suggestions, ideas, etc. are welcomed.

Thanks,
W

 

[Magnum88C]

A lot of S&B ammo is loaded very hot. If other ammo doesn't give you a problem, then that might be it.

 

[Cosmoline]

Yes, S&B is quite hot in general and about half my Mosins both Russian and Finn have cratered the primers or even burst them from time to time. I've also noticed that the primers tend to be set flush, whereas Russian made rounds and surplus ball ammo tends to have indented Berdan primers. The Mosin's pin was designed to hit the deeply-set Berdan military primers rather than flush Boxer primers. I've noticed cratering problems with my handloads even when I know they're not hot.

 

[Ukraine Train]

If it's an issue of primer depth you can always adjust your firing pin.

 

[W Turner]

Ukraine Train - I had considered the firing pin depth/protrusion, but it checked out when I checked in with the supplied gauge. I would rather not change the depth for ammo that I will only use for hunting. Esp. when I shoot so much more surplus ammo!

Thanks everybody,

W