300, will do! It will get to my FFL Friday or Monday, and I'll measure and check then. I'm not a model 12 expert by any measure, but I think you're right on the 13 5/8 based on the research I did before buying it.
Kid, I've heard the same about hevi shot, looks like that or bismuth are my options for waterfowl, but the 3" target and game rounds are looking elusive...
