Posted by Mike G on February 13, 1999 at 19:40:46:
In Reply to: competition does use outside measurement.... posted by One Hole on February 13, 1999 at 17:55:58:
Right RG, the device gives you the reading of the group on your calibers, you don't have to subtract bullet dia. because it measures center-center. I picked one up at show 2 years go, it also has the magnfying attachment which really helps.