Low prices on the Ruger GP100 4" Stainless .357 Magnum start at Champion Firearms-
Strength. Simplicity. Ruggedness. Introduced in 1985, the GP100 was designed to replace Ruger's highly successful Security Six revolver series. Built on a larger, heavier, more robust frame, the GP100 was engineered specifically to take the long term abuse of full powered .357 Magnum loads. The GP100 incorporated some major imrovements over its predecessor. First is the cylinder locking system, which is latched to the frame at the crane, as well as at the back of the ejector rod. Ruger calls this a "triple lock" cylinder. The purpose of the bolt at the bottom of the cylinder is to prevent cylinder rotation, not keep the cylinder in the frame. Unlike the cylinder latches, the bolt retracts when the cylinder turns. Another improvement is a stub (half size) grip frame that replaces the conventional grip frame, allowing the attachment of a one-piece grip of practically any size, shape or style. Grip panels don't attach to the sides of the GP100's grip frame, as with traditional revolvers. Instead, a one-piece grip slides over it and is attached by a screw through the bottom of the grip.
The investment cast frame has no removable side plate; most of the internal parts are attached to the trigger guard assembly, which is removed from the bottom of the frame. Most revolvers on the market are built on a removable side plate design that is over one hundred years old. They were built to handle low pressure cartridges of the period. When magnum cartridges came along in the '30s, the old designs were just made larger to handle the extra intensity of firing magnums. Still, magnum revolvers built on the removable side plate design tend to loosen with heavy use. Ruger’s double action revolvers have always been built without a removable side plate. This adds needed strength to the frame area around the cylinder, without adding bulk to the revolver.
The Ruger GP100 uses the transfer bar ignition system, which makes carrying a revolver with a fully loaded cylinder absolutely safe until the trigger is intentionally pulled. To swing out the cylinder, press in on the button mounted in the frame's left recoil shield.
For iron sights, the GP100 uses a rear adjustable system that allows for rapid target acquisition.
This heavy duty workhorse features a solid stainless steel construction with a satin finish, and includes its signature 4" full underlug heavy barrel. The action is driven by a traditional double / single design and unlike other revolvers, Ruger exclusively uses higher quality music wire springs.