A muzzleloader can be a rifle, shotgun or handgun. They all load from the muzzle only and use black powder or a replica black powder. There are several differnt types of ingnition systems too.

For hunting first thing I suggest to you would be to check the regs in the state your going to muzzleloader hunt in and see what they define a muzzleloader as. The definition varries greatly from state to state as to what is legal for hunting.