Sinclair chamber gauge, correct use

[targaflorio]

I just measured my 300 win mag chamber by cutting down a case and using the sinclair 308 plug. I got 2.6575". That's a long way from the 2.610 trim to length for 300 win mag.
What should I trim my brass to? 2.620"' the book max case oal? And what about the brass that is shorter?

 

[Cory Lee]

Re: Sinclair chamber gauge, correct use

From what I understand you want to let it expand to chamber length -.010" or so. Creates a better seal.

I usually trim new brass to a uniform length. Whatever the shortest one I can find is. Then don't worry about it for a while.