Doe Dumper

I dont think I have ever measured a piece of Remington brass that was the same.[:@]

Roskoe

I usually don't trimcases until I have fired them once.

Ought Six

Usually, if one full length resizes new cases, some trimming can be done. That being said, it is not necessary to trim new cases until fired. The mouth will be uneven, but that hardly matters until the case is fire formed.