Heck I don't even measure it. Sort by headstamp, well other than tossing steel/Al and the ones with the stupid internal ledges, I reload it all. ( 9mm with crimped primer pockets goes to the recycle can, I have plenty of .223 to remove crimps from.) I do case gauge all 9mm ammo I use for matches since I use scrounged range brass. What is right for me may not be right for you. If you have the time do a couple tests for vel (if you have a chrono) and accuracy. 1 Mixed headstamp vs same headstamp 2. Trimmed vs non trimmed Once you have the results you can decide if it is worth sorting or trimming. If I was loading SD loads (I prefer to use factory ammo for SD) I might sort by head stamp.