Blackpowder Barrel Info. Needed

[DenverDuck]

I have a new barrel sitting around that I don't know what it is and she has no markings.

Octagon and no taper, tapped on one end for a breech plug. Bore measures about .612" so my question is; would that maybe be a 58 or 62 caliber or what?

Many thanks in advance...

[Alan Block]

rifled or smooth? 20ga?

[Eljay]

It does sound like 20ga. You would probably use a .600 ball and a cloth patch. You would vary the thickness of the cloth as part of the load tuning but .015 would be a good starting point.

[DenverDuck]

Rifled.