The star gauge wasn't invented until the early 1900s, but one would think they would have slugged a barrel as we do. Perhaps it was thought close enough was good enough. To a certain extent that's true. Then along came Hudson and Pope bellyaching about undersize bullets and oversize bores. I shot some 168s out of a .310 groove diameter barrel and wasn't expecting much, but got a 1" 100yd group. I imagine the rifles with bad bores that came back from Cuba and the Philippines were simply rebarreled rather than broached. After all, that's sorta the point of having a barrel that screws into the receiver. It's likely also the reason we often find 92s and 96s with like new bores. Like new, but still often oversize. Boring seemed to be pretty consistent, most all mine are .301" bore, t'was the rifling depth that varied.
"I have sworn upon the Altar of God, eternity hostility upon all forms of tyranny over the minds of man." - Thomas Jefferson