The Heckler & Koch P7, which used to be called the PSP for “Polizei Selbstlader Pistole,” has a powerful round but is small enough to fit in a pocket or holster. Because of this, the breech must be locked, and gas pressure is a good way to do this. Usually, a recoil spring is under the slide, and a guide rod is inside the spring.
This guide rod, however, has been precisely machined, and it slides within a cylinder that fits snugly in the frame just above the trigger as the slide recoils. When the handgun is shot, high-pressure gas enters the cylinder through a port between the cylinder and the barrel, and the pressure exerted by the gas prevents the slide from moving rearward.
Design and firing mechanism
Once the bullet has left the barrel and the gas pressure drops, the rod can move back, forcing the gas out of the cylinder, into the barrel, and thence out to the atmosphere. After that the action is that of any other blowback automatic pistol.
As the gas pressure decreases after the bullet has exited the barrel, the rod can slide back, releasing gas from the cylinder into the barrel. After then, it functions just like any other blowback automatic pistol.
To prevent accidental discharge while transporting a loaded firearm, the firing pin is not cocked during the recoil stroke but is instead managed by a grip on the butt’s leading edge. The firing pin is already heated up when the firer grabs the butt and squeezes the grip, so his continued pressure is unnecessary once the weapon is in the cocked position.
But when he lets go of the gun, it is no longer ready to shoot. So, it can be carried safely with a round in the chamber and used right away. If the shooter drops it while it is uncocked, it will be cocked again before it hits the floor.
While the rear sight is stationary, the foresight can be adjusted, and the rear sight can be slid laterally to get a zero. Both sights include white dots inlaid to help with alignment in low light, and glowing ‘Betalight’ markings can be added for nighttime use. The Heckler & Koch P7 is a uniquely designed handgun that can be quickly and easily disassembled with a stripping tool.
Technical specifications: Heckler & Koch P7 (PSP)
Manufacturer: Heckler & Koch GmbH, D-7238 Oberndorf/Neckar, Germany
Type: delayed blowback, semi-automatic
Caliber: 9 mm Parabellum
Barrel: 4.13 inches (105 mm)
Weight (empty): 27.07 oz (785 gm) with empty magazine
Capacity: 8 rounds