The Ruger GP100 is a single/double-action revolver chambered in .357 Magnum / .38 Special with a 4.2-inch barrel and a 7-round cylinder. It weighs approximately 40 oz (2.5 lbs) with an overall length of 9.5 inches. The finish is satin stainless steel. 
 

Key Specifications: 

• Brand: Ruger 
• Model: GP100 
• Caliber: .357 Magnum / .38 Special 
• Action Type: Single/Double Action 
• Capacity: 7 rounds 
• Barrel Length: 4.2 inches 
• Overall Length: 9.5 inches 
• Weight: 40 oz (approx. 2.5 lbs) 
• Sights: Fiber Optic Front; Adjustable Rear 
• Finish: Satin Stainless 
   

Detailed Features 

The stainless steel frame carries a satin finish that resists corrosion and holster wear. The DA/SA action allows the shooter to choose between double-action for fast first shots and single-action for precision. The fiber optic front sight and adjustable rear sight pair for quick target acquisition across different lighting conditions. 
 
The cushioned rubber grip with hardwood inserts absorbs recoil and maintains control during extended shooting. The transfer bar safety prevents discharge unless the trigger is fully pulled. 
 

Usage Notes 

The 4.2-inch barrel is a practical middle ground between the compact 2.5-inch and longer 6-inch configurations. It provides a longer sight radius and more velocity than the snub-nose variants without adding the overall length of the 6-inch barrel. At 40 oz. it is manageable for range use and home defense while being less suited to daily concealed carry than smaller alternatives.

Owners of the Ruger GP100 in .357 Magnum with the 4.2-inch barrel describe a reliable, accurate revolver that draws from Ruger's established reputation for durability.

Build quality is the most consistent positive. The satin stainless finish holds up through heavy use and weather exposure, and the action runs smoothly across both .357 Magnum and .38 Special loads. Trigger feel in double and single action is described as predictable and comfortable for range work.

Accuracy at standard defensive and target distances is consistently reported as strong. The 4.2-inch barrel gives enough sight radius for reliable performance at most practical distances. The versatility of running .357 Magnum and .38 Special is frequently mentioned as a practical advantage for both practice and defensive use.

The revolver's weight and the 4.2-inch barrel keep it in a range where most owners use it for home defense and range shooting rather than everyday carry. Price comparisons with other revolvers land favorably for most buyers who weigh performance against cost. Some owners develop an attachment to the classic revolver format that the GP100 represents.