I don't think the OP meant for you to go back simply to kill. I think he meant more along the lines of, if you went back simply to be there and live, and happened to be a part of one of the "old west shootouts" that the movies love to portray. Granted they didn't happen nearly as much as the movies portray, but gun fighting did happen on occasion. The guns you bring back can be used for hunting, protecting your ranch from rustlers, hostile Native American, etc. The premise of the OP isn't just "what would you bring to go back and start slaughtering people". Try to think a little.