Based on the description and characteristics, the Heavy Assault Rifle is more like a heavy machine gun than an assault rifle by early 21st century standards. It fires from a closed bolt, but is belt fed. Additionally, it is stated that it fires a .50 caliber FMJ round. Judging by the cartridge's appearance, it is roughly equivalent to the .50 BMG round, which has historically only been used for heavy machine guns and sniper/anti-material rifles. Its size and power might explain why it has been supplemented by the Plasma Rifle. However, at least some UAC soldiers utilize a form of power armor, which might allow a single user to fire the high powered, high capacity gun as if it were an assault rifle, and the Doom Slayer in his Praetor Suit is more than capable of doing the same.