7.62x54R ammo question

[Vicious-Peanut]

I fired some Bulgarian heavy ball through my 91/30 and had great performance, no failure to fires or anything. However around the firing pin strike (right on the edge) there is a little rim that is elevated. I have my firing pin protrusion set at .090", so that shouldn't be causing anything. All the rounds look this way, so it isn't just one or two high pressure rounds. I don't think it is a problem, but just wanted to run it past you guys.

I can't get a picture since my camera can't get a good zoom on it because it is so little.

 

[Bartkowski]

I have seen that with a few types of guns before and don't think it is a problem.

I assume someone will know more about this than I do, but I would just keep shooting.

 

[esmith]

Are you saying the edges of the primer's are protruding after being shot? If so, it's normal for them to be a little bulged, but only a little. If they start to pop out completely then your firing pin protrusion is too much.

I have some spent bulgarian right here that also appears a little bulged.

 

[Vicious-Peanut]

Hard to explain without a picture, but here goes.

Around the little 'valley' made by the firing pin right on the edge of the dent is a little lip, let me draw it in pain.

 

[Bartkowski]

I believe he means around the crater made by the firing pin the metal has been forced up slightly, so that the edges of the crater are higher than the rest of the primer.

 

[Vicious-Peanut]

Exactly, thank you Bartkowski.

 

[res45]

Can you post a pic sounds like you may have had some gas leaks around the primer pocket you can see an example of that on page 47 of th lyman #48 manual or if your primers are cratering it could be pushing metal up around the firing pin hole. Most of the Bulgarian HB will have cratered primers like this.

 

[Vicious-Peanut]

Those are EXACTLY what mine look like, so it is normal for this ammo?

 

[res45]

For Bulgarian yes its pretty hot stuff,I pulled the bullets on some of mine dropped the powder charge a little and they shoot like this. I don't know if the other brands of 54r do the same or not.



I also use the same case and powder to make hunting rounds using several different bullets.

 

[Sgt.Dusk]

All factory ammo is making a crater like that for me. No matter if its some bulgarian surplus or Lapua. So I think its normal for 7,62x54r to crater a little.
I reload much lighter charges and dont get that with them.

 

[RugerOldArmy]

It looks, to me, like there is a gap around the firing pin on that rifle. This is why gunsmiths 'bush' firing pins, to eliminate the slop/space. On a hot load, some of the primer metal is forced into that space.

 

[NCsmitty]

According to surplusrifle.com, the min. firing protrusion is .075 and max is .095. IMO, the firing pin hole is a little oversize and causing your cratering but isn't a real dangerous situation. I did as res45 and pulled my bullets and dropped the charges by 4gr. and then reinstalled the bullets and recrimped them with my Lee crimper. A little easier shooting and safer pressures. My ammo is the '86 Albanian brass case.

NCsmitty

 

[res45]

I dropped mine down to about 46 Grs. even I noticed setting the bullet to a consistent depth and having a balanced charge also increased the accuracy form spreads to decent groups.

 

[Cosmoline]

I've had that issue with many Mosins. It isn't a problem unless the primers are getting pierced or there are other signs of excess headspace. Cratering itself can just mean you have a an extra large pin hole.

 

[AmishFury]

it's not uncommon... i have some that do and some that don't