The MK,Lk, Wolverine, and Littlehorn are all basically the same as the Bighorn. The MK has a squared off receiver. And they have a shorter barrel than the Bighorn. Bore is a big issue and make sure you get Western ignition. Make sure it has sights or is drilled for sights. 50 cal is pretty much the standard anymore. More accessories and bullet choices are available for the 50 than any other cal. Watch Gunbroker. Lot's of good deals at times.