460 Rowland is 1/16" longer than 45ACP and is thicker in the web. You need the brass for it. Here is Clark's link it should answer all your questions. I have one and its a fun gun. I have not hunted with it yet but over the chrony its very impressive. I have been to clarks in LA and its a good shop, they do good work. Check out Taffin's article on it also on the site...........Sam