Trying to authenticate this Parker

[OH Osthaus]

the proofs are from Birmingham UK - there were several gunmakers in Birmingham with the last name of Parker starting in the 1700s- I expect your expert knows little of muzzleloaders, if the barrels are rough, cutting a couple inches off isn't going to help.

[edgarspencer]

Originally Posted by Rick Losey

I expect your expert knows little of muzzleloaders, if the barrels are rough, cutting a couple inches off isn't going to help.

Taking what Rick has said, the thickness of the barrels, at the muzzle, means little apart from being more vulnerable to denting.