At the end of 1986 Fabrique Nationale (a Belgium arms factory) realised it was time for a replacement of the 9mmx19 cartridge and its firearm in the military. The 'non-frontline' soldiers (drivers, medical personel etc..) were at that time equipped with 9mm handguns, which were unable to penetrate modern body-armour. FN started their project of the 90's.
This project included to design a new sub-machine gun (personal defence weapon PDW) with the following main features;
The achievements for the ammunition in comparison with the .223 and 9mm should be;
The new weapon produced by FN was the P90 submachine gun. The associated ammunition was the SS90.
The P90 weapon fires from a closed bolt, this improves accuracy. The P90 uses a blow back mechanism (for lower costs and it makes the maintenance easier) The fire selector can be put on save, single shot or fully automatic. In the fully automatic position it fires single shots when the trigger is pulled slightly and it fires fully auto when the trigger is pushed further. (two-stage trigger)
The P90 is completely ambi-dextrous, and eject the fired cases downwards.
The 50 round magazine is made of transparent plastic and placed on top of the submachine gun. The cartridges are placed in the magazine in a 90 degrees angle compared with the firing direction and are rotated just before entering the chamber.
The P90 is compact, handy in close quarters, and provides rapid target aquisition and outstanding hit probability out to 150m.
The Five-seveN handgun
To complete the project in a real weapon system, FN also designed a pistol, called the Five-seveN.
The cartridge (SS90) was adjusted and modified to fit in the handgun. The bullet was reduced in length, resulting in a round with a reduced total length. The round was adopted as SS190.
The pistol is for the greater part designed from composite materials, resulting in a very light handgun.
The operating principle is a delayed blowback system, a single action trigger and a 20 rounds magazine capacity.
The weapon system was designed for military use, but representatives of the law enforcement (police, SWAT teams etc) were really impressed by the performance of these weapons. They included these weapons in there range of armament.
The sale of these weapons and ammunition to civilians is for safety reasons restricted.