Ruger GP100

GP100
Ruger KGP-141 with speed loaders of .357 ammunition.
Type	Revolver
Place of origin	United States
Production history
Manufacturer	Sturm, Ruger & Co.
Produced	1985–present
Variants	See Models
Specifications
Weight	36–45 oz (1,000–1,300 g)
Length	8.5 in (22 cm) 9.5 in (24 cm) 11.5 in (29 cm)
Barrel length	3 in (7.6 cm) 4.2 in (11 cm) 6 in (15 cm)
Cartridge	.357 Magnum / .38 Special .327 Federal Magnum .44 Special
Action	Double-action revolver
Effective firing range	55–110 yd (50–100 m)
Maximum firing range	+/- 550 yd (500 m)
Feed system	6-shot cylinder (.357 Mag & .38 Spl) 7-shot cylinder (.327 Fed Mag) 5-shot cylinder (.44 special)

The GP100 is a family/line of double action six-shot (.357 Magnum) seven-shot (.327 Federal Magnum) or ten-shot (.22 LR) revolvers made by Sturm, Ruger & Co., manufactured in the United States. It was introduced in 1985 as a second generation of the Ruger double-action, exposed-hammer revolvers intended to replace Ruger's Security- / Service- / Speed-Six line. It was made stronger with the intent to fire an unlimited number of full-power .357 Magnum rounds and has been produced in a number of variations with three basic barrel lengths (3 in / 76 mm, 4 in / 102 mm, and 6 in / 152 mm), various barrel profiles (full lug and half lug), fixed or adjustable sights, and in blued carbon steel or polished stainless steel.

The GP100 was an evolution of an earlier Ruger double-action revolver, the Security Six. The first significant change was introduced with the Ruger Redhawk and that involved a new locking mechanism with a lever on the crane rather than using the end of the ejector rod to lock. Another change was the shape of the frame. Traditional revolver frames had exposed metal at the front and rear of the grips, with the frame determining the shape of the grips. This meant that to have a round butt concealed carry version and a square butt holster or target version of the same gun usually meant having two different frame shapes. The GP100 series, instead, used a small rectangular "peg" grip large enough to enclose the hammer spring and strut. The grips could then be any shape desired, as long as they were large enough to enclose the peg. This was not a new innovation having been used by Dan Wesson and, to some degree, by High Standard revolvers that predated the GP100. The Dan Wesson patent (U.S. Patent 3,683,535) was granted in 1972 and Ruger's patent (U.S. Patent 4,625,445) was granted in 1986.