Huey, with all respect, if you don't know the difference between a boxlock and a sidelock yet, you probably shouldn't be buying SxS's yet. If you do buy, it's going to cost you some serious cash to learn that difference and a host of other things about these vintage guns. I speak from experience here, having invested significant tuition in my own SxS education. You have found one of the best and most inexpensive places to learn right here.....take full advantage of it. Read and ask questions. Go to a gun show with a knowledgeable member in your area. Visit one of the dealers recommended here just to look and learn. It will save you big money and frustration down the line.