Tom Peterson, the original designer of the Stoney Point 'Chamber-All' (now known as the Hornady Lock-N-Load OAL tool) told me that the difference between the measured 'touch' distance with that tool would be from .010-.015
shorter than the
true touch point....for consumer safety.
I broke out my original 'Chamber-All' tool today and used it in one of my 30BR barrels. Then did my normal 'Touch Point/Wheeler Method'.
T.P./'Wheeler Method: 1.642"
Chamber-All Method: 1.631"
Pushing as hard as I could on the rod on the Chamber-All, the most I could get was 1.633". By the way, the original rods were aluminum, not the current plastic ones.
Good shootin'

-Al