Why are shot gun bores so clean?

[TFLeader]

Was at a local GS and looking at a shotgun close to 100 years old. The bore looked like it came off the production line. I am not a big shotgun collector but I have a few old ones and they are also mirror bores. The GS owner said it's because shot guns do not have rifling. Not sure I buy that answer....

 

[Trenchgunner72]

Mostly because shot rides the barrel in a plastic cup. And, because there is no rifling to collect copper deposits, lead and powder residue. Non-corrosive priming used in shotgun shells going way back helps too.

 

[spcantwell]

maybe just shot less? put 4 boxes of shells though a shotgun and its a party, 100 rds though a rifle and its not even a start

 

[roadkillrob]

Its like it gets bead blasted every time you shoot it!

 

[MisterHappy]

An old shotgun, especially if it was a good one, will have had a finely polished and lapped bore.

Even before the advent of plastic shot cup wads (in the 60's) if lead were to accumulate on the surface of the bore, a bronze brush will remove it.

If the previous owner(s) cleaned it immediately after shooting corrosive ammo, and kept the leading at bay, then there's no reason why a 100-year-old bore should not look minty.


As for a bore looking dirty after firing....that's what Hoppe's is for.