I'm buying a 300BLK upper to supplement my 9mm SBRs. I've reloaded >150K rounds of 9mm on my 1050/Mark VII, but nary a rifle round; I've got the discipline. I don't anticipate large volume and I'm retired so a single stage will be fine. Lots of good info on die sets, etc. Since I intend to start with either a)new 300BLK brass when I can get my hands on same or b)reformed 223 brass, assuming I can get several (5-6?) firings out of this brass how often would the brass need to be trimmed? That's the one step of the process that doesn't in any sense transfer over from my pistol cartridge experience.