
Fabriqeu Nationale P90 began as the Project 9.0 in response to NATO's call for a personnel defense weapon (PDW) which would better equip tank crews, artillery crews, etc., whose duty would not include the use of a full-size weapon. As part of the NATO requirement.
The P90 is built around the 5.7x28mm ammunition  which  was developed specifically for this gun. The cartridge is unique because, after penetrating a body, it tumbles end-over-end so that it causes a larger wound. Also, the military and law enforcement variant  can  penetrate  most  modern body armor.The P90 is blowback operated and fires from a closed bolt.
The magazine lies above the barrel and holds up to 50 ballets in two rows in horizontal position pointing to the left.

