45-70 Barrel Dimensions for Paper Patching

[Rbertalotto]

I drove a pure led, oversized bullet from chamber to muzzle and from muzzle to chamber a while ago. This the only accurate way to measure the groove diameter and to check for uniformity . That I understand for lubed bullets. The issue was coming up with a relatively consistent way to measure bore diameter.
The hole gauge was only used to confirm the pin measurement.
Thanks for the comments, much appreciated!