I have the Weaver 92A Contender base on my 500 S&W barrel and it works great!
I drilled and tapped my barrel and installed the four 6-48 screws with 242 Loc-Tite (blue). I mounted a Burris 1.5-4X pistol scope in Weaver Quad Lock rings and it has performed flawlessly.
GOOD SHOOTING!
Slufoot