The dents are most likely from a mallet being used on it to seat a tight fitting ball in the muzzle.
Just curious Stanton, are you a muzzle loader?
Yes, Ken. Competed in NMLRA competition rifle (round ball) matches for a long time, somewhat successfully. Won several state championships, and shot a 50/50 at Friendship. (Everybody wants one of those easy "50" Friendship patches
)
Also hunted deer with a couple of my roundball rifles until I lost interest in deer hunting, and shot doves and wild quail with muzzleloading double shotguns.
All that is mostly in my past, though I do pull a front stuffer out every now and then and use it.