jonk
02-02-2010, 10:59 AM
I made a chamber cast on my Lebel Berthier carbine the other day. This gun never shot well with anything (granted, awful sights and a worn muzzle don't help) but I figured I'd give her one last shot before selling.
Ordinary dies size a case to accept a .323 bullet. The original french bullet measured something like .325.
So I have a mold that drops at .332 for my 8X56R Steyr, and I wanted to see if that was in play or not.
The neck diameter of a loaded round (spec) is .350. Assuming that with a .323 bullet, I needed to have the chamber measure something like 12/1000" more to allow for bullet fit and release, plus a deep enough throat to permit seating at a reasonable depth. So let's say a chamber dimension of at least .362" at the neck.
Ok, so the cast revealed.....drumroll..... .375"! Yow, that thing could take a full 338 pill with no issues, chamber wise! The throat was a bit better diameter wise. I don't think it would take a .338 slug much beyond the chamber itself. It was pretty long though- even seated with just the gas check below the case it chambered no issues on the Lee 329 bullet.
Now the bore on this beast slugs .328". So no wonder I had bad results with a .323 either cast OR jacketed. The .332 as dropped from my Lee mold doesn't QUITE fill the throat but it does come close I think. I have an 8mm Karabiner that I could beagle to see if that monser would do the job.
So we have a big old mouth and a deep throat. Linda Lovelace would be proud...:mrgreen:
Ordinary dies size a case to accept a .323 bullet. The original french bullet measured something like .325.
So I have a mold that drops at .332 for my 8X56R Steyr, and I wanted to see if that was in play or not.
The neck diameter of a loaded round (spec) is .350. Assuming that with a .323 bullet, I needed to have the chamber measure something like 12/1000" more to allow for bullet fit and release, plus a deep enough throat to permit seating at a reasonable depth. So let's say a chamber dimension of at least .362" at the neck.
Ok, so the cast revealed.....drumroll..... .375"! Yow, that thing could take a full 338 pill with no issues, chamber wise! The throat was a bit better diameter wise. I don't think it would take a .338 slug much beyond the chamber itself. It was pretty long though- even seated with just the gas check below the case it chambered no issues on the Lee 329 bullet.
Now the bore on this beast slugs .328". So no wonder I had bad results with a .323 either cast OR jacketed. The .332 as dropped from my Lee mold doesn't QUITE fill the throat but it does come close I think. I have an 8mm Karabiner that I could beagle to see if that monser would do the job.
So we have a big old mouth and a deep throat. Linda Lovelace would be proud...:mrgreen: