What is frosting?

[Rogue Hunter]

Reading the descriptions on a couple auctions they mention "frosting" on/of the barrels. What does this mean? Define, please?

thanks,
RH

[OH Osthaus]

a grey discoloration in the bores, not shinny

but certainly not to the point of pitting

[Rogue Hunter]

Probably not saying this correctly but, is this now a quality of the barrel metal and can't be removed without removing some of the metal of the barrel? Also is this a serious problem?

Guess I've never seen this in a guns' description.

thanks,
RH

[OH Osthaus]

i have seen it used much more often in describing rifle bores

with any issue - I would think the gun needs to be evaluated individually