Thread: Fire forming 270 to 280ai

Originally Posted by 7mm tragic

Sooo, I should be able to use a Lee die set designed for the "original ackley cartridge" and it will be fine for sizing brass in my saami spec chamber.

I have been able to determine the amount of shoulder set back needed by chambering my fired cases and comparing the difference between the ones that allow the bolt to close with no resistance vs the ones that don't.

Using this number I should be able to safely determine if my brass is indeed sized correctly?

Tell me if I'm missing something

If you have the dies then size a fired case and see if it bumps the shoulder back far enough to close the bolt