Safe load for small ring mauser

[jeb]

My son was given an 1891 Mauser that has been modified. The barrel has been cut back & partially rechambered to .308 Win. From the cartridge base to the forward end of the taper it is .308. From the end of the taper forward it is 7.65 mm.

For reloads he uses .308 cases w/the neck opened up to take a .311 inch dia bullet.

Long explanation but now to the question. I have a 1895 Mauser rebarrelled/rechambered to .308 Win. To maintain safe pressure levels on the 1895 action I use loadings for 300 Savage.

My question: does the bullet diameter increase from .308 to .311 (same weight) change the pressures given in the 300 Savage loadings?

Thanks in advance for your help.

Jeb

[BudT]

Dont shoot the .311 bullets in the .308 barrel even with the reduced loads the larger bullet will push the pressures up and maybe up to much. In a nutshell yes it can raise the pressure. HTH

[jeb]

To BudT.

I was not clear in my description. The barrel of the 1891 is the original military barrel which uses .311 dia bullets.


Jeb

[BudT]

My question: does the bullet diameter increase from .308 to .311 (same weight) change the pressures given in the 300 Savage loadings?

Jeb[/QUOTE]

That was the only question in your post so that was the question I gave a answer for. I shoot a 7.65 Mod91 Argentine mauser and am aware that they use a .310-312 dia slug. It is possible that I don't have a clue what your trying to ask. You didnt ask about the Argentine you asked about the 95.

[Parashooter]

All else being equal (charge, primer, case, bullet weight/materials, rifling configuration/twist, bore finish, ambient temperature, etc.) a .311" bullet fired in a .311" barrel will give slightly less pressure than a .308" bullet in a .308" barrel. This is primarily because the larger bore has greater volume. In practice, this difference will be too small to observe, obscured by one or more of the other variables.

Now, if you were asking about .308 vs. .358 Win., that would be a different story.

[jeb]

THANK YOU PARASHOOTER.

As usual I am better informed for having asked a question on this forum.

Many thanks.

Jeb