Mr. Dillon’s fine emporium has a serious power trimmer available. Mine wears an external speed control so the RPMs can be tailored to the diameter and nature of the brass. If you are not doing big batches, there are many other alternatives.

A LIGHT inside (eases bullet seating) and outside (slicks up feeding) chamfer also gets rid of any burrs from trimming.

Also pretty-much essential in semis and full, (smoke ‘em if you’ve got ‘em), goodies, is a “light” neck crimp, using the Lee “Factory Crimp” die specific to your calibre. Rounds get shuffled back and forth in the magazine at every shot; you do NOT want bullets moving from their “magic” seated position before you squeeze off another potential “X”.

For single-loaded “slow-fire” ammo, mag-shuffle is not a huge problem, but if you are using compressed loads of slower-burning propellants behind long, “heavy” bullets, the neck crimp will help retain the bullet for a few extra micro-seconds as combustion gets up steam.