Nobody makes bases to fit as many guns as Weaver. Yet each base is machined to tight tolerances for a custom fit. They're designed to fight the effects of recoil with a square cut notch that precisely mates to the sturdy cross bolt in every Weaver Detachable Ring. Custom hardened fastening screws come with every Weaver base.

2 of these are required to mount a scope

Beretta Pintail slug gun, front or rear
Colt Sauer, front or rear
Enfield cut down, front
Herters U9 round receiver, front
Mossberg 1500 and 1700, front
Raptor Arms, front
Remington 700, 721, 725 and 78 long action, front
Remington 700 and 78 short action, front
Remington 700 muzzleloader, front
Sauer 200, front or rear
Shilen flat top receiver, front or rear
S&W 1500, 1600 and 1700, front
Weatherby Mark V except .240 Mag and Vanguard, front
White W series, rear