That’s crazy! I’m using Talley’s on my M70 .458 Lott with no issues, other than my own mistake mentioned above. I’m shooting Federal safari loads with 500 gr TBBCs at 2300 fps out of a 22” bbl. I wonder why in the world you are having these kinds of problems? It sounds like you’re going above and beyond to ensure a good mount.
First mounts and rings I used were Warne as there has been a lot of good reviews on AH about them.
After shooting about 15 rounds each, Hornady 500 grain softs and solids, the little metal rear insert broke and the front one bent.
Purchased a set of Talleys, mounted them, and went to the range with 10 rounds each Nosler 500 grain softs and solids and 20 rounds of test reloads. Tested the reloads no sign of any problems. Then I switched to the Noslers 5 rounds and the scope moved. Rest the scope, tightened down all the base screws. Fired 3 rounds, group was about 1 1/2 inches in the bull ring, none in the dot. Fired 3 more rounds, first round in the dot and the other 2 went wild, okay shooter error (so I thought). Checked the scope and all seemed good. Fired 3 more rounds, well at least 2 in the 12 inch black ring. Fired 2 of the next 3 rounds and couldn't fined the holes anywhere. Looked at the scope to see if it moved again. The rear base mount was no longer affixed to the rifle. Removed the scope and finished shooting up the remainder of ammo using iron sights.
Purchased a second Talley rear base. Rebored, counter sinked, and rethreaded the holes for screws 2 sizes larger and threads longer, just enough not to interfere with the bolt, than the original screws. When the rear base seperated off the rifle it messed up the holes and threads in the rifle receiver. Filled the threads with blue loc tite and torqued all the screws to 20 foot pounds.
Short of welding/soldering the bases this should have held the bases in place, so I thought. Reloaded 5 beginning loads, and 5 light mid loads, on hand 10 rounds of Nosler factory loads.
First 3 rounds in the magazine were the beginning loads. First round sent the scope into my face, putting a cut near my right eyebrow, another cut on the bridge of my nose, which may have been caused when the scope hit my glasses. The scope hit the ground (dirt and gravel) about 3 feet from me.
As I initially said, Luckily the scope wasn't damaged. As for my face a couple of pieces of gauze and medical tape.
'Not a big fan of the "clamp-to-receiver" system for mounting. Bases and rings work for me in heavy calibers and/or super accurate guns. The only gun I own with similar is a Ruger 22-250 which of course has very little recoil, and a few .22 LR Mags with similar. Not an optimal design. But are they steel?? And, is it cast or machined?? I'm certain they'll be sending you the latest-greatest in Titanium if you promise to clean the gun....Do yourself a favor-when you get your free replacements-sell them and get Alaskan or Talleys. 
