You will gain exactly "squat' by sorting quality rimfire ammo, either by weight or by rim thickness. BUT......Run of the mill, inexpensive, bulk-type ammo may be different. I have tried using both methods on some Standard velocity PMC that I had a couple of bricks of. When shooting at targets, the stuff that I applied both methods to did shoot tighter groups in a 20 group sample. That being said, it was a lot of work to get results somewhat inferior to those I could have got from just shooting a good quality round. I don't bother these days. Just shoot a good quality round (Super Club), like CZ452 says. Regards, Eagleye.