The cva elkhorn has the proper breech in the box. It also has your choice of #11 or musket nipple. I have a T/C Black Diamond, but because they aren't made anymore I recommend the Knight Big Horn. Stainless steel, and an adjustable trigger. It also comes with a couple different breech plugs, and your choice of nipple. They're about $100 more than the CVA though. Knight also make a kit with the Wolverine, but it's not the quality of the Big Horn. Traditions is making a break action gun that is legal, but there has been some trouble with ignition, so I don't recommend them.