Last month I decided to try to reload and fireform my 22-250 brass over to 6.5 Creedmoor with my standard 6.5creedmoor load with 120gr bullet (I use 250 Savage load data for my 120gr 6.5CReed loads) and I was finding problems with splitting case necks and excessive case stretching with the brass at the cartridge head.
fast forward 30 days to today's trip to the range with freshly loaded 6.5-250 brass (22-250 brass when run through a 6.5 Creed sizing die reforms the neck and shoulder to the proper diameter and neck size but the 250 body taper is still there)
25gr of IMR 4895 and Lyman's 140gr 266469 mold bullets was the suggested 2000fps load for the day.
My goal was to simply blow the shoulder and the cartridge body out to the 6.5 Creedmoor cartridge shape (Yes, I know the reformed cartridge has 1mm shorter case neck from factory brass but I was not going to let 400 pieces of 22-250 brass be sitting on a shelf for no reason.)
Thankfully, my rifle decided to shoot a very nice group for the day in fireforming these cartridge cases. I may save this load for future 100 yard NRA Highpower rifle matches! A couple of clicks up and boom, I'd be eating the center out of this target.
Oh, and the brass formed perfectly this time around.