Miller, I doubt anyone would think of a pinfire , or a 22 long rifle, or any other you mention like a Benelli when a gun was referred to as a percussion gun. The common use for that term, Percussion gun, is a muzzleloader fired with a cap.
I see the confusion caused by Drew's reversal of the pinfire and percussion. He, of course had the terms in a reversed order. I think we can possibly come up with the dolphin motif on earlier systems including flintlock, and others earlier than that. It was just a description of what inspired the hammer shape.
