22 bore ??

It could well be a 20 gauge with an undersize bore. 22 = .596" & 21 = .605". These bores may have accepted a 22 gauge plug gage but not a 21 gauge. Assuming the barrels have a 22 proof mark on them the bores could have been anywhere between those two dimensions. "Or", it may just be a typo.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra