PP-90

The PP-90 was developed by KBP in the early post-Soviet period as a folding 9 mm submachine gun. Its concept resembled earlier Western folding machine-gun ideas: carry the weapon in a compact rectangular form, then unfold it quickly for automatic fire. Modern Firearms describes the concept as an attempt to copy the general idea of the American Ares FMG. The result was unusual but limited in success, showing the tradeoff between concealability and practical handling.

Technically, PP-90 is a 9x18 mm Makarov submachine gun with a folding body that encloses the barrel and working parts when carried. Once unfolded, it operates as a simple close-range automatic weapon. The folding concept improves discreet carriage but creates compromises in sights, controls, rigidity, and readiness compared with a conventional compact SMG. It is therefore more interesting as a concealment concept than as an all-around fighting weapon. Later Russian PP-90M and related designs tried to improve practicality.

Operationally, PP-90 was suited to undercover, protective, or special tasks where compact carry mattered more than sustained firefight performance. Its limitations made it unlikely to replace more conventional submachine guns. The design is still valuable historically because it shows Russian experimentation with collapsible weapons during a period when police and security requirements were changing. For the equipment page, PP-90 should be framed as a niche folding SMG, not a standard infantry machine gun.