All muzzles are crowned. It's a prerequisite to shooting well. Some muzzles have a recessed crown to better protect the rifling at the muzzle. Some also have a "deep dish" crown, which also protects the rifling at the muzzle and provides a cosmetic enhancement. FA has offered the first 2 as standard on their guns, depending upon the caliber (my 252 and 1 of my .357's has the recessed crown as standard). The "deep dish" is offered as an extra cost option. One of my .500WE's has one. I doubt that the deep dish adds much if any of an accuracy enhancement to a straight wall pistol cartridge barrel, but it IS attractive. Deep dish crowns are common from SSK, Magnaport, and Gary Reeder.