Re: 1 piece vs 2 piece bases
You both make good arguements, I think the OP hit it on the head when stating (when machined properly), if not, the fit could be uneven & when torqued, theoretically could cause undue stress/torque on the receiver. Even when using 1 piece it's still a good idea to at least check ring alignment to determine if lapping is necessary (if you aren't using the Burris rings w/inserts). Call me overprotective but 2 piece bases scare the heck out of me on big, hard recoiling uber magnums, just seems weaker in my mind, I guess a guy could pin them to the receiver, that would make me feel better.
I am in no way trying to say 2pc bases are inferior, just posting my thoughts!