The 3-inch stainless Model 66 served federal agencies and plainclothes officers who needed magnum capability in a compact package. It provided a meaningful velocity advantage over the 2.5-inch barrel while remaining concealable in a shoulder holster. Type: Revolver Action: Double-Action Caliber: .357 Magnum Capacity: 6 Year introduced: 1970, USA Weight: 35 oz Overall length: 8.5" Status: Active Intended use: Carry, Duty, Plainclothes