Ruger introduced the GP100 in 1985, but it was not their first DA/SA revolver. Back in 1972, the automatic pistol had yet to take over the police and personal defense markets. Revolvers with the typical twin trigger functions—cocking the hammer with the trigger, called double-action or cocking it with the thumb, known as single-action—were viable products. S&W dominated the market with fighting revolvers made on three frames, with Colt in second place. Ruger saw the potential here, particularly in the light of their well-developed investment casting process.
In four-inch guise, the GP-100, with its full under-lug barrel and shrouded ejector rod, has just the right looks to make gun owners giddy and bad guys incontinent. According to my wife, “I feel safe just looking at it . . . it’s big, powerful, and easy to use in a stressful situation.”
Over 1,500,000 Six Series revolvers had been sold by the time the line was discontinued in 1988. The replacement for the Six Series was the GP100, introduced in 1985 and the subject of this review. If the Six Series can be equated to the S&W "K" frame line, the GP-100 can be equated to the S&W "L" frame line. It is built on a larger, heavier frame designed specifically for the .357 Magnum cartridge.