Common Smoothbore Calibers

So I was pondering the other day about smooth bored rifles during colonial times (think prior to 1820). I see a lot of talk about bigger bored guns used for fowling and large calibers on French muskets and the Brown Bess. What would have been the most common calibers for smoothbore longrifles?

You know; I’ve often heard that some smooth rifles were the result of the rifling being damaged over time. Then, they would just polish it out for a slightly larger bore. I would imagine many would have been originally smooth bored with rifle characteristics like a cheek piece and so on. You have to imagine that those rifling tools were large and hard to come by in some areas. The cheapest way to build a rifle, is to not rifle it. If an economy rifle is what they were going for, I’d imagine the bore wasn’t too large. More shots per pound.

Most common? I have no idea. But the ones I've seen from back then were generally smaller, sometimes much smaller, than their sister fowling guns. I know of a few that range from about .40 to .50, maybe .54, One hunter I know of uses a .45 smoothbore flintlock and it "big time" does the trick on any small or flying game.

Between the KRA discs and the handful of books I have I'd say .50-.54 is a safe average.