I use split necks to make my whisper brass, just do the major cut at the bottom of the shoulder and run the brass, one pass through a RCBS, FLSD, then in a 3 way cutter on a RCBS Pro Trimmer. My brass is already swaged. No annealing is ever needed. I shoot mostly 230g cast, PC with a can.
I have a steady supply of trimable brass, with the cats I shoot.