Trim Length

[jawshunting]

I need to know how much to trim off 6 BR Norma,Lapua) brass. What does the OAL of the brass need to be. Mine is measuring about 1.556, 1.557 before trimming. Jaws

 

[Preacher]

The best way I have found to do what your asking is to open up a primer pocket enough to slip a Hawkeye borescope into the case while it is in the chamber and you can see exactly where the end of the case will set.
Most times the length is OK as is and usually don't need to be trimmed any shorter...
Usually folks will trim to the shortest one in a batch and leave it like that, but unless you can measure the length exactly, like when using a Sinclair trim gauge your just guessing.
Chamber lengths varies to much for a specific answer........

 

[Ackman]

Most people trim unnecessarily, just because they think it's the thing to do. Sinclair has plugs that go into the end of a case with a cut-back neck. Get one for every caliber you shoot. These things will show exactly how long the chamber really is. It's an eye opener to find out how much space there is past the casemouth.