Musk. I have used 38/357 jacketed pistol bullets in my 2 rebored 8x57 to 9(.358)x57's and have had a merry hell of a time getting most of them to feed from the mag. The extractor hooks have not been beveled so I have to feed them from the magazine and most revolver bullets are so blunt and short they won't go up the feed ramp properly so the CRF doesn't work. I have had decent luck using 9mm RN bullets though w/acceptable accuracy and Unique. They do like RCBS cast 200gr FN's (longer nose) w/2400 at 1800+ fps on deer ect. It is then about a 35 Rem. in a heavier rifle, quite comfy.- Muddy