Trickymissfit
Well-Known Member
"Especially cases coming out of large factory chambers with a bulge on one side and if that bulge sits on the gauge supports ."
I don't care how 'accurate' my runout is from a mechainst's point of view, what I want to see is no wiggle on that gage.
Given your recognition of how difficult it is to properly support a cartridge so the results are of runout rather than case inaccuracies drove me to make my own runout gage. Wanting to know the relitive angular displacement of the bullets led me to a system I've seen no where else.
The only machined surface on a case is the extraction groove. I have a 1/16" thick bit of sheet teflon with a "V" cut that the extractor cut drops into. A similar teflon V notch is adjusted to support the bullet just outside the case mouth. The dial indicator plunger is positioned as close to the meplat as possible but not where pointing irregularities could influnce the gage. Slowly turning each cartridge gives me consistant high and low readings at the same places, total indicated runout, over most of the bullet's exposed length and that's all I need.
try tooling balls sometime. Minimal area contact and max runout with them is about .0005" or less. If you get the ones with a shoulder on them they are extremely close.
gary