I just came into ownership of this shotgun. A very well kept J.C. Higgins - Model 101.7. I'm not knowledgeable with shotguns, as I've only ever handled them. Never owned or fired one before. So as I'm looking this over I noticed that one of the barrels seems larger than that other. Not much bigger. One of them a dime could fit, in the other it can't, but just barely. I'd like to point out that I'm not a hunter (not that I'm opposed to hunting, just never had the opportunity and don't know where to start) or a shotgunner, so I don't know much about chokes. Can anyone help me out here? What should I be firing out of this shotgun, and why the difference in barely diameter/choke? Thanks!