If you stop and think about it for just a minute, consider what goes on when the rifle goes off and the bullet starts to move. First thing that happens is the old law of physics that says things move apart...the bullet goes forward, the rifle goes back, and the scope, if there's any clearance at ALL, sorta slams back and forth in those grooves in the base. That material won't take if for very long, especially in a rifle that gives it a head start, like the .500 does.
Those bases will work fine, but, they'll work much better if you find rings that fit those grooves very closely. When I use Weavers, no matter the caliber, if there's any slop at all between the base groove and the ring, I push the bottom of the one ring against the forward edge of the base's groove and the other against the back, before, and while, I tighten the binding screw. It has worked well so far for me, even with them "cheap" Weavers on the .500. A close, or tight fit works better.