Just mounting the scope properly with a windage-adjustable rear mount is problematic...because of the lateral mobility (if only during the mounting process) of the rear ring, it's easy to end up with unintended force flexing the scope tube. The system's only real strength is its adaptability in compensating for imperfect placement and drilling of the mounting holes, but its weaknesses are pretty egregious.
Saturday a customer arrived with these rings. Job one for his whole rig was checking torque on every fastener I could find, one being these screws. I put just enough to make them click on the wrench, which was into 45 in/lbs. I alternated left and right.
We never left 100 yard paper with his rig, because it was all over the place. I reached in the truck and pulled out my 7mm-08 with a hand load, great scope, terribly durable Weaver style rings, and EGW pic rail. What-do-ya-know, he went 200 to 800 with zero misses then put his rifle in his truck. 30 year old Win 70 in .300 Win Mag, and Hornady ELD-X 220 gr. What do you think I thought the major problem was with his rig?
Those crap rings and base.