Ya for some reason they do not rate this one as 50 cal compatible. Not sure why, its the highest priced scope in the lineup.
These big 338, 375, 408 and 416 rifles may not have the shear recoil energy as the 50 cal class weapon systems but because of their lighter weight, hey are not that far off, especially with the better muzzle brakes we are using today. In my experience, its the negative G forces that are most likely to rip a scope apart unless its built to specifically handle negative G forces. If this scope will do it, it would be another good option for a mid priced scope from what I am hearing about it.
I really like the reticle design and the FFP and it has good vertical adjustment for the price range.
I was curious so I contacted SWFA. They claim the 5 x 20 is definitely rated for the 50.