It served as the standard-issue sidearm for the Imperial Russian Army (replacing older Smith & Wesson models), then the Red Army/Soviet forces through WWII, and even lingered in limited use by security services (like the NKVD) into the post-war era. Key Features and Design Caliber: 7.62x38mmR Nagant (a unique rimmed cartridge where the bullet is seated fully inside the case for the gas-seal mechanism) Capacity: 7 rounds (one more than most revolvers of the era) Action: Double-action/single-action (most military models were double-action; some early enlisted versions were single-action only for cost savings) Barrel length: 4.2 inches (110 mm) Overall length: About 9.3 inches (235 mm) Weight (unloaded): Around 1.8 lbs Sights: Fixed front post and rear notch (simple and rugged) Unique mechanism: The standout feature is the gas-seal system. When the hammer is cocked (or in double-action trigger pull), the cylinder slides forward slightly, pressing the cartridge case mouth into the barrel's rear to create a near-perfect seal. This: Prevents gas leakage from the cylinder gap Boosts muzzle velocity by ~50-100 fps compared to standard revolvers Allows effective use with a suppressor (one of the very few revolvers that can be suppressed without major gas loss; suppressed versions existed for special units) The design is mechanically complex compared to simpler revolvers but extremely reliable in harsh conditions (mud, cold, neglect)-a big reason it endured so long in Russian/Soviet service.