Forming 257 Raptor from 222 Rem Mag

The TC can headspace off the extractor to form the cases. You might need to square the mouths afterward. I figure it should work but try a few before going wild. Use virgin brass or risk splits and blown shoulders. Sometimes but not always.

really gain anything by going in that direction. You still have to open up the mouth of the case and fireform it, the same as you do with the 204 case.I like the Hornady 204 brass as it is already annealed which makes it less likely to crack and split.