7.62x54R low pressure

[TrickyDick]

OK, so last Sunday I fired 20 rounds of 7.62x54R. They're my reloads, and they shoot fairly well. But I noticed that when I extracted the spent casing, there was soot on the neck, and the primer wasn't flat.

The load I use is 47.3gr of IMR4320, 150gr .311" Sierra SP spitzer. 2.900" OAL

I'm thinking I could reduce the OAL to 2.850-2.875" and perhaps, that would pick up the pressure a little bit.

Any thoughts?

 

[entropy]

This is normal with low pressure loads in any bottleneck caliber. The neck doesn't expand enough to seal, but the shoulder does. No big deal, it comes off in tumbling.
I reload 7.62x54R also, and there are some light loads with 125 gr. AK bullets and unique or Red Dot that do this too. I also like IMR 3031 for light loads, it keeps the pressures up enough so the neck doesn't soot.

 

[FROGO207]

I like .311 diameter 180 grain bullets and 50.1 grains H 414 for my loads. I would bump up the charge a bit and the soot will go away but with a good accurate load. if you have one, I would put up with sooty necks.
Pushing in the bullet will not raise pressures fast like in a shorter pistol case so the coment about bumping up the charge.

 

[LeftyTSGC]

I also use the .311 180gn bullets with 43gn of R15 at OAL of 2.975 gives around 2365fps a good medium load. I occasionally get soot around neck, but as stated not a problem. My 150gn bullets with 43gn of R15 at OAL of 2.87 give around 2387fps. Normally its a clean shot but if sooty i dont worry, just clean them. Both of those powder loads is what i get best accuracy with at 100yds for my rifle.

LeftyTSGC

**These are my load recipes for my rifle, use at own risk**

 

[Reloadron]

What you are seeing is normal. For what it's worth the Sierra 50th Anniversary Edition loading manual with the 150 grain Spitzer over IMR 4320 reflects a Start 45.7 grains and a Maximum Load of 50.3 grains. Your load data comes in a little above the Start Load. I don't see it as unusual for the case necks not to expand enough to block gas, especially when loading a .308" diameter bullet. Matter of fact, even if you pushed the load up a little I doubt the black soot on the necks would go away.

Ron

 

[TrickyDick]

I figured the load was a little light, but I also take in account that the 7.62x54R cartridge headspaces on the rim and not the shoulder. So when I full length resize them, I know there's a gap between the chamber and shoulder.