I have 4 rifle barrels, a .45-70 that is .4567-8 or so, a .35 Whelen that is .3565, a .44 mag. that is .431, H&R said that is the target dimension, and a .308 that is .310, H&R said that is within spec.'s as all of their dimensions are +- .002.
So I have a big .44mag., always thought it was .429, a .45-70 and a .35 Whelen that are slightly undersize and a .308 Win. that is at the extreme of the tolerance range, I suppose 3 out of 4 is not really bad, but I wish they had tighter tolerances.
At least they are American made.
Don :roll: