Like the M-16 and most other modern assault rifles, the FNC fires the NATO standard 5.56mm cartridge. It uses a detatchable 30 round box magazine and can also accept STANAG style magazines used by the M-16 series. Internally, the FNC borrows heavily from the AK-47 gas system with some improvements over the original Soviet design.
The FNC is currently used by the Belgian armed forces and is liscensed to Sweden and Indonesia as the Bofors AK-5 and Pindad SS1, respectively. Once called "the free world's assault rifle," the FNC is generally regarded as a sound, reliable design, although the stiff trigger pull of around 10lbs somewhat hinders accuracy and shooter comfort.
For more information:
" class="external">http://remtek.com/arms/fn/fnc/
http://world.guns.ru/assault/as24-e.htm.