At what point do #8 scope mount screws become highly desirable as opposed to #6s?

Thinking about getting the mounts right for a .458 AR. Recoil could be in the 70-75 lb-ft range.

I have only seen 1 scope base shear it's screws and that about 25 years ago on a 460 Wby Mag. After drilling out 3 broken stubs, I re-attached his base using good quality 6x48 screws and it has held ever since. Loose or strained screws, poor fit and heavy optics do more damage than the amount of recoil. If you would feel more comfortable using 8x40's then go for it. I think regardless what size screw you use, that you make sure that the base fits with perfect contact front to back, and that a good quality screw is used.

Everyone and everything says 6-48 until they strip or break, then use 8-40.

I have worked on lots of guns and never had a problem with a 6-48 yet.
I have lots of 8-40 taps and screws if it ever happens.

The sniper guys start out with 8-40 mount screws, and tighten up the rings to the mount with big bolts


What does it all mean?
Alvin Toffler in 1970 said that the Hell's Angels cannot wear wing tips, or they would be out of uniform.
The 8-40 may be required costume for some sniper guys.