The Gauntlet

Smith & Wesson Model 66

Clint Eastwood carried a Model 66 with 2.5" barrel that has a square butt profile, instead of the round butt, more common in the short-barreled version of this revolver.

Smith & Wesson Model 66 with 4" barrel - .357 Magnum

Ben Shockley (Clint Eastwood) with the Model 66

Sondra Locke with Shockley's Model 66

Browning Hi-Power

Cops can be seen shooting Browning Hi-Powers:

Cops carrying the Browning Hi-Power in "The Gauntlet"

Smith & Wesson Model 10

Several cops in the final shootout carry this revolver:

Smith & Wesson Model 10 Revolver - .38 Special

Cops carrying the Model 10 in "The Gauntlet"