"The true measure would be to load, say, 10K rounds on both a T-7 and another turret and put the rounds on a concentricity gauge."
Sorry Steve, the true measure is to load as many rounds as you think you need and then put them in the target. Gauges tell you what you may have done wrong, targets tell you for sure.
I'm just beginning to flirt with a high-power target rifle. It shows a lot of promise if I could just get my heart to stop beating, but I load my .308 rounds on a Lee 3-hole turret press. I load them one at a time, just like I did when I was using the single-stage press. I carefully measure as many things as I can and then let my targets tell me if I'm doing things right. This morning, with an intermittant cross-breeze, I managed four groups (out of six) of less than 1 MOA.
I also use it to load 7mm, 8mm, .38 Special and .357 Mag. I haven't had a problem yet that I could blame on the press. If I have any massive resizing to do, I use the single-stage, but I think that's just common sense.
Lee presses look like a POS, but unless you mistreat them they'll do the job. Someone should work out the cost/benefit ratio some time: A $100 Lee press with very occasional broken parts which you would have to pay for against a $500 Dillon with it's free replacement parts. How many Lee parts would you have to buy to equal the price of the Dillon?
