Remington 51 - Design Details

Design Details

The layout of the Remington 51 is similar to the Walther PPK pistol in the use of a stationary barrel and recoil spring surrounding the barrel. However, the unique feature is the use of a locking breech block within the slide. When the pistol is in battery, the breech block rests slightly forward of the locking shoulder in the frame. When the cartridge is fired, the bolt and slide move together a short distance rearward powered by the energy of the cartridge as in a standard blowback system. When the breech block contacts the locking shoulder, it stops, locking the breech. The slide continues rearward with the momentum it acquired in the initial phase. This allows chamber pressure to drop to safe levels while the breech is locked and the cartridge slightly extracted. Once the bullet leaves the barrel and pressure drops, and the continuing motion of the slide lifts the breech block from its locking recess through a cam arrangement, continuing the operating cycle. One can insert a dowel into the barrel and push on the breech block. It will only move a fraction of an inch and stop against the lugs. Only manually retracting the slide or firing a cartridge opens the gun. The Remington Model 51 was the only production pistol to utilize Pedersen's type of operating system.

Because the breech is locked, this pistol can handle greater pressures than a blowback firearm yet without the size and weight penalty of other locking systems. The design also allows the recoil spring to be placed around the barrel making for a shorter profile gun. Lighter operating parts and longer lock time provide less felt and actual recoil. A lower bore axis gives less muzzle rise which also lowers felt recoil. A fixed barrel allows for greater accuracy and reliability as well as simplifying construction compared to other locking systems. Overall, this system is lighter than a blowback, simpler than any conventional locking mechanism, and has less recoil than either of the other systems.

The Remington Model 51 uses an internal hammer and features a single-action trigger. A unique combination lever on the rear of the grip-frame acts as a safety, bolt hold-open device and bolt release. This is in addition to the grip safety, magazine safety disconnect, and relatively heavy trigger pull. The grips are held on with spring-tensioned studs rather than screws. Not a single screw is used in the entire pistol. Pedersen was greatly concerned with human engineering and developing a comfortable grip angle for his pistol while not sacrificing the slim profile. Field stripping the pistol is cumbersome but not overly complicated.