The M249 is the PUBG light machine gun that uses 5.56mm ammunition.
The weapon is PUBG’s adaptation of the real M249 Squad Automatic Weapon, itself derived from the Belgian FN Minimi design. In the game, it uses green 5.56mm rounds and is known for a large magazine capacity, high sustained fire, and strong vehicle-destruction potential. Those strengths make it particularly effective when suppressing enemies or defending against a push.
The M249 is commonly confused with other PUBG light machine guns because their roles overlap. The DP-28 uses 7.62mm ammunition, while the MG3 uses 7.62mm and is associated with airdrop loot. The RPD is not the standard counterpart in PUBG’s main weapon roster. Ammunition caliber is therefore the cleanest way to distinguish the M249 from these heavier-cartridge weapons.
The real-world M249 is formally associated with the designation “Light Machine Gun, 5.56 mm,” which explains both its name and its ammunition choice. PUBG preserves that central identity while balancing the weapon for gameplay.