The FN CAL ("Carabine Automatique Légère", or Light Automatic Carbine) was first demonstrated in 1967. It was an early attempt of the famous Belgian company Fabrique Nationale (FN) to produce an assault rifle chambered for then-new American 5.56mm small-bore, high-velocity cartridge. The FN CAL rifle was designed with mass production in mind, with extensive use of steel stampings and plastics. However, the production life of this rifle was relatively short, and only about 12 000 of FN CAL rifles were manufactured before FN closed the CAL production line in 1977 and switched to more promising design, known as FN FNC. Most of these rifles were sold in Latin America and Africa. The main problems, associated with FN CAL rifles, were complexity of manufacture of certain parts, insufficient reliability and somewhat complex maintenance procedures.
The FN CAL assault rifle is gas operated, select-fire weapon. It uses short-stroke gas piston, located above the barrel. The locking is achieved by rotating bolt with multiple radial lugs that engage the barrel extension. Receiver is made from steel stampings and assembled from two parts (upper and lower), hinged at the front. Trigger unit is equipped with 4-position safety / fire selector, and allows for single shots, 3-round bursts and full automatic fire. The charging handle is located on the right side of the receiver, and moves along with the bolt group when gun is fired. Rifle can be fitted with fixed plastic butt or side-folding metallic butt. Standard sights consist of front post and L-shaped rear sight with two apertures (for 250 and 400 meters range). The muzzle compensator / flash hider is shaped to accept rifle grenades; the US-made M203 grenade launcher can be fitted under the rifle, if required. Feed was from proprietary box magazines with 20- or 30-round capacity.