MtAl
The gauge rods (plugs) were in .01mm "steps" and the numbers stamped on the barrels for the bore (not groove or bullet) diameter were not precise diameters. There is not much difference between 0.4400 and 0.4399. The "book" indicates the proper diameter bullet is .446", but the Mod 71 I shoot takes a .454" bullet to shoot decently (I don't shoot black powder in it) and it won't chamber unless I size the neck in a 444 die after seating the bullet. From what I can see of the dimensions you reported, you shouldn't need to go through that "goat roping" to get it to shoot.
Mike
