Basically there are two main requirements...no scopes, and the nipple must be "exposed to the elements." So that eliminates popular guns like the Omega and Encore, and many other inlines. Oh, also the 209 shotgun primers are not legal. And, bullets must be all lead. If you want an inline, the T/C Black Diamond is legal and that's what I have. I also have a traditional style muzzleloader, a Lyman Deerstalker. The best thing to do would be to go to a store that sells them, like Sportsman's Warehouse, and look at what they've got and talk to somebody there who knows what's legal and what's not.