Just wanted to give a quick shout out for a great product. I bought RockJag's holder last year and have since cut my first chambers with it. I'm using and old SB Heavy 10 lathe that's 71 years old. I've cut 4 chambers with his holder so far and have had awesome results with no more than .0001" TIR for each chamber give or take. I turned a buddy on to it and he's getting the same results. It just works wonderfully. Thanks John for a nicely priced and more importantly...a very effective tool.