Re: Hornady concentricity guage any good?
I have one....I seem to have up to 10-thousandths run-out, using Plain-Jane RCBS dies. Easy to correct the run-out and very fast with the concentricity gauge. I get down to less than two thousandths very fast with loaded ammunition, and have seen a marked decrease in groups size. That said, my buddy borrowed it and he felt that it opened his groups up (his ammo was loaded with competition dies, and run-out was around 1-4 thousandths with most less than two thousandths). I was shocked at the runout in off the shelf hunting ammo, and I corrected all of it I had. Hope that helps!