7.62x54r issues with my mosin

[majew]

I went to the range today with my room mate and we fired about 200 rounds between our mosin nagants. I did notice that some of the shells seemed to have a small crack in them but only in the russian surplus rounds we were firing.

Some one at the range said it was a head spacing issue in the rifle. After firing a few more rounds (not the best idea) and checking all of them only the Russian surplus (and not all of them) had cracks. I'm guessing the issue is with the rounds and not the rifle. Is this ammo safe to keep using? Is there really a head spacing issue or just cheap ammo?

 

[SSGSAD]

My guess, is ammo, IMHO, if it were the rifle, I would think, that all the brass would be cracked... Someone, more knowledgeable, than I will either confirm, or not .....

 

[johntheplinker]

Yep, just the ammo. Very common with surplus in this round, and nothing to worry about.

 

[majew]

the guy at the range made it sound like the rifle or the rounds could hurt us if we kept shooting them.

 

[David]

I've seen that too. I have a few Mosins and it doesn't seem to be a particular gun. I check all the chambers with a field gauge before I fire the guns, so I don't think it's an excessive head space problem. All I shoot is surplus ammo.

 

[HavokCycle]

missing important detail - what ammo?

 

[BiscuitNaBasket]

missing important detail - what ammo?

We were shooting Russian surplus / Bulgarian 7.62x54r . If that's not what you mean by detail then I in turn ask you what you mean by detail?

 

[johntheplinker]

I've seen that too. I have a few Mosins and it doesn't seem to be a particular gun. I check all the chambers with a field gauge before I fire the guns, so I don't think it's an excessive head space problem. All I shoot is surplus ammo.

Nothing at all to do with headspace. Basically on a Mosin the headspace is approximately the distance from the face of the bolt to the far side of the case rim, so the shoulder area doesn't even figure into the equation. Possible the shoulder area was cut large but if that was the case then every spent casing would be cracked. About the only to determine if that is the case you would have to do a chamber casting.
What causes the cracks in surplus ammo is when the commies made the cases they didn't bother annealing the shoulder area. Since the metal has been work hardened by the forming process there is a lot of stress in that area and has become brittle over time. The round is fired and instead of stretching to fill the chamber, that area of the case instead cracks. The body of the case is still soft enough to stretch so it does so and seals off the gases.

 

[Tomfoolery]

^^ This. +1. What he said.

You're going to get that if you fire a lot of surplus. I've seen the crack run up to rim or down the side of the case. I even had one that split in almost a spiral, saved it for a keychain. It harms nothing. I've had them come out of my PSL, Mosins and when I get a PKM they'll get spit out of that too I imagine.

 

[solution_zero]

John is right, it is the way the Russians manufactured the ammo. You will see it a lot with surplus 7.62x25 ammo too.

 

[SideArmed]

Were you guys at Atterbury today? down around lane 15 or 16?

 

[in625shooter]

I had 2 Mosins and like others have said it happens with some surplus ammo. Don't worry about it!

 

[BiscuitNaBasket]

Were you guys at Atterbury today? down around lane 15 or 16?

Yeah, we started at 36 for the pistols then switched to lane 16 and spent a good 2-3 hours and 220 rounds with the Mosins.

 

[SideArmed]

Yeah, we started at 36 for the pistols then switched to lane 16 and spent a good 2-3 hours and 220 rounds with the Mosins.

Oh, Ok. In that case, You are welcome.

 

[BiscuitNaBasket]

Oh, Ok. In that case, You are welcome.

for ???

 

[SideArmed]

for ???

My buddy and I were on 17 & 18 and cleaned up all the spent 7.62x54r brass for ya, after we got tired of tripping over it.

 

[BiscuitNaBasket]

My buddy and I were on 17 & 18 and cleaned up all the spent 7.62x54r brass for ya, after we got tired of tripping over it.

Thanks bud. The kid next to us planned on collecting that, but I guess he changed his mind.

 

[majew]

that guy did pick up like 100 casings and said he was going to get the rest, I guess he didn't. Sidearm, what were you firing?

 

[BiscuitNaBasket]

Nothing at all to do with headspace. Basically on a Mosin the headspace is approximately the distance from the face of the bolt to the far side of the case rim, so the shoulder area doesn't even figure into the equation. Possible the shoulder area was cut large but if that was the case then every spent casing would be cracked. About the only to determine if that is the case you would have to do a chamber casting.
What causes the cracks in surplus ammo is when the commies made the cases they didn't bother annealing the shoulder area. Since the metal has been work hardened by the forming process there is a lot of stress in that area and has become brittle over time. The round is fired and instead of stretching to fill the chamber, that area of the case instead cracks. The body of the case is still soft enough to stretch so it does so and seals off the gases.

Thanks for the explanation John. and thanks to everyone else too.

 

[SideArmed]

that guy did pick up like 100 casings and said he was going to get the rest, I guess he didn't. Sidearm, what were you firing?

We were down on the pistol range when you guys were there. By the time we got down to the Rifle side there was only one other guy with his son shooting down there.

I had my AR out on the rifle side, but down on the pistols we had: Sig1911, Ruger SR9c, GSG1911-22, & Taurus 24/7. My buddies had a couple of guns also. One had a new HK P30, I really like it, think I may have to look into the HK line of guns.