PP-90 - Design

Design

The PP-90 (short for Pistolet-Pulemet obrazets 1990, Russian: ПП-90 – Пистолет-пулемет, "Machine Pistol model of 1990") is an automatic-only weapon that uses the straight blowback method of operation, chambered for the 9x18mm Makarov cartridge. The weapon bears a conceptual resemblance to the 9 mm FMG submachine gun made by the American company Ares.

The PP-90 consist of the following main groups: the receiver which houses the barrel, action (bolt and recoil mechanism), safety, fire selector switch and supports the pistol grip with magazine well and the shoulder rest. When carried in the stowed position (the bolt is in its forward, closed position) the pistol grip and magazine are folded under the barrel in line with the bore axis and covered by the folded stock body. The folded weapon resembles a cuboid with the following dimensions – 270x90x32 mm, devoid of any protruding elements, enabling easy concealment. To ready the weapon for firing the stock is pivoted out (simultaneously the pistol grip with magazine, trigger and trigger guard deploy), the safety is disengaged and the bolt cocked. The bolt’s cocking handle is installed at the rear of the receiver and is accessed from beneath the stock.

During the design phase, emphasis was placed on safety when operating the weapon. It is impossible to discharge the firearm in its folded position or when the stock is not fully deployed. The PP-90 also has a manual safety and fire selector. The safety toggle, installed on the left side of the receiver housing, has two settings: a top “P” position – indicating the weapon is safe and the bottom “O” setting – automatic fire. The "safe" setting ensures the bolt catch is disabled mechanically. The weapon’s internal safety mechanism features a drop safety that prevents the weapon from firing when dropped with a loaded chamber.

The submachine gun is fed from a detachable 30-round box magazine, placed in a well inside the hollowed pistol grip. The magazine catch is located inside the heel of the pistol grip.

For aimed firing the PP-90 uses flip-up iron sights (notch and front post), which lie flush with the receiver housing’s top cover when folded down. The threaded barrel can also accept a sound suppressor.

The submachine gun with spare magazines and a cleaning brush is carried in a holster that can be slung from a duty belt or shoulder rig. The weapon can also be used with a sling.