Operating mechanism system. The P7 is a
semi-automatic blowback-operated firearm. It features a unique gas-delayed blowback system modeled on the Swiss Pistole 47 W+F (Waffenfabrik Bern) prototype pistol (and ultimately on the Barnitzke system first used in the
Volkssturmgewehr 1-5), which used gas pressures from the ignited cartridge and fed them through a small port in the barrel (in front of the chamber) to retard the rearward motion of the slide. This is accomplished by means of a piston contained inside a cylinder located under the barrel that opposes the rearward motion of the slide until the gas pressure has declined—after the bullet has left the barrel—hence allowing the slide to end its rearward motion, opening the breech and ejecting the empty cartridge case. The chamber has 18
flutes that aid in the extraction process by allowing combustion gases to flow between the fired case and the chamber walls, preventing the case from "sticking". The drawback of this system is that the breech opens slightly prematurely to allow the slide to initiate its rearward motion. The high temperature gases channeling into a tube located between the chamber area and the trigger made the early versions of this pistol uncomfortable, according to some, due to the heat generated after extended firing. The advantages of this system are a simpler manufacturing process due to the absence of a locking system and a high mechanical accuracy due to the barrel being fixed in the frame; the barrel is not subject to any sort of lateral or vertical movement during the operating cycle as with the Browning cam-action systems common to many locked-breech pistols.
Features The P7's spring extractor is contained within the slide, while the fixed ejector is a surface on the slide catch. The grip of this pistol features a built-in cocking lever located at the front of the grip. Before the pistol can be fired, this lever must be squeezed; thus this lever acts as a safety. The pistol is striker fired. Squeezing the cocking lever with a force of cocks the firing pin. Once fully depressed, only of force are required to keep the weapon cocked. The weapon is then fired by pressing the single stage trigger rated at approximately As long as the lever is depressed, the weapon fires like any other semi-automatic pistol. If the lever is released, the weapon is immediately de-cocked and rendered safe. This method of operation dispensed the need for a manual safety selector while providing safety for the user carrying the pistol with a chambered round, and increased the speed with which the pistol could be deployed and fired. The trigger and firing mechanism's method of operation (and the unique slide catch) were protected by , issued on January 2, 1979. The P7 is fed from a single-stack
box magazine with a capacity of 8 rounds, which is held inside the firearm's frame with a release located at the heel of the grip. After the last round has been fired, the slide will remain open thanks to a slide catch that can be released by pulling the slide further back or pressing the squeeze cocker. The firearm uses a fixed,
polygonal rifled barrel (
hexagonal with a 250 mm twist rate) and a fixed notched
iron sight with contrast dots that enable shooting in low-level lighting conditions. The pistol is completely ambidextrous and two-handed use is enhanced through the use of a profiled and enlarged trigger guard. The trigger guard was equipped with a synthetic heat shield that protects the shooter from excessive heating and a lanyard attachment loop was added in place of the previous magazine heel release. The firing pin and its bushing were also changed. == Variants ==