Finally got myself a .357 barrel here on the forums (thanks Paul), I had a 9mm custom made for a 300 Whisper project and thought I'd try it out on a single shot rifle. I had the barrel cut down to 16.5" and threaded 1/2x28 and let me tell you, this thing is too much fun. I've been shooting Wal Mart Federal 38 Special 158grain lead bullets and this thing just plain rocks! It sounds like a healthy air gun going off, it's a little bit louder than my subsonic .22lr going off. So far I'm getting about 2" groups at 100 yards using an old Simmons 44mag scope I had laying around. Anyone thinking about getting a 9mm can should definitely consider getting a .357 barrel to go with it.