7mm ultra mag trim length & crimp?

[coozfever]

I am new to reloading a bought the lee case trimmers. hodgon website says trim to length is 2.840 and my lee trimmer is trimming them to 2.838 will 2 thousanths matter?
I am also wondering on the brass i shot once and saved there seems to be some kind of crimp mark around the top of the neck. Do I need to crimp these when I reload them or just sat them to length?
Thanks foer help!!

 

[jezzolo]

Fine with the length. No need to crimp it. That crimp mark is from the factory.

 

[Anonymous]

Though a crimp is usually not needed I'd test for push pressure on a loaded case to see if a crimp is needed. Just simply seat a bullet and push it against a table top to see if the bullet holds firm. Also chamfer and deburr your cases, I've seen roughly 3000 PSI elevation on some cases that haven't been chamfered and deburred. I hope that helps.