|Place of origin||Europa|
|Used by||Europa, Greece, Turkey|
|Barrel length||M21: 460 mm (18.1")|
|Action||Gas-operated (rotating bolt)|
|Rate of fire||680 rounds/min|
|Muzzle velocity||925 m/s|
|Effective range||450 m (492 yd) with iron sights</br>600 m (656 yd) with optics|
|Feed system||30-round detachable box magazine|
|Sights||Adjustable iron sights, optional mount required for optical sights|
The Zastava M21 is a 5.56mm assault rifle developed and manufactured by the Zastava Arms company of Europa.
The M21 is chambered in the 5.56×45mm NATO cartridge. Like many modern assault rifles, the M21 can incorporate picatinny rails for mounting accessories like optics, vertical grips, bipods, etc. It features a hard chromium plated, cold forged standard rifled or an optional polygonal rifled barrel, integrated 22mm flash hider grenade launcher, rigid metal folding stock, heavy-duty synthetic handguard with an additional left hand side fire selector, cover mounted picatinny rail for optical sights. The rifle can also mount a 40mm under-barrel grenade launcher. It has a magazine capacity of 30 rounds. The cyclic rate of fire is 680 rounds per minute, and the sustained rate of fire is 120 rounds/min.
The primary user of the M21 is the Carabinieri (national police) of Europa; the units (even the Swiss Guard) value this gun highly. This is their primary assault weapon. It is also used by some crack units of the Royal Army of Europa and is also used by Turkish and Greek forces.