Heavy Assault Rifle

"With high velocity rounds, the Heavy Assault Rifle is ideal for hitting fast-moving targets."

- Arsenal description

The Heavy Assault Rifle, or HAR, is a weapon featured in DOOM.

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.

Tactical analysis
The Heavy Assault Rifle is a very well-rounded weapon that can be useful in virtually every situation, but is rarely the best weapon for any particular situation. It has a medium rate of fire, higher than that of semi-auto or pump action firearms, but lower than that of the Plasma Rifle or Chaingun. Its rounds are relatively low power, but they have the highest velocity, as well as good accuracy. However, the Heavy Assault Rifle suffers from crosshair bloom during sustained firing, meaning the longer the trigger is held down, the less accurate each shot becomes. This means the user is restricted to increasingly smaller bursts the farther away a target is. The weapon is effective at staggering early game demons, or even taking them out entirely with headshots, which can prove life saving on Nightmare.

Campaign
"Although recently superseded by the Plasma Rifle as the UAC's standard issue weapon, the Heavy Assault Rifle is still in widespread use due to its dependable mechanical firing mechanism, high accuracy at long range, and an abundant supply of ammunition. The weapon is effective at all engagement distances, and is best used against a solitary target, unless a micro missile modification is present. The standard issue ammunition is a .50 caliber FMJ round."

- Codex Entry

Ammunition
The Heavy Assault Rifle shares its ammo pool with the Chaingun. The player can increase their max ammo cap by using Argent Cells and allocating its power to "Ammo" subsystem.

Tactical Scope
"The Heavy Assault Rifle can be fitted with a parallax compensating telescopic sight that allows for multiple zoom levels and gimbal mounted recoil stabilizers. The high accuracy of the UAC-TS3 turns the HAR into an excellent sniper rifle that is capable of firing multiple rounds without creating unmanageable recoil."

- Tactical Scope Codex Entry

Micro Missiles
"A multi-chambered cylinder located under the primary barrel can be loaded with up to six HMX missiles. These small but deadly rockets were designed to deliver multiple payloads to a single target, but can also be used to subdue multiple targets within a tight kill zone. The missiles will detonate shortly after making contact with any surface."

- Micro Missiles Codex Entry

Each missile costs 6 (2) bullets.

Multiplayer
The Heavy Assault Rifle can be unlocked in the multiplayer at level 2 (it's also available to use in level 1 by choosing "Ambusher" default loadout). The player spawns with 100 bullets (120 is the max ammo). The weapon features two fire modes:
 * Primary Fire - Fully automatic assault rifle with a digital scope. Each shot does 10 damage and 14 for headshot.
 * Weapon Mod - Enables the digital scope for extended range combat (Hold the Weapon Mod button).

Trivia

 * If no ammo is available, the Heavy Assault Rifle's belt will be visually empty.
 * The weapon shares ammo with the Chaingun despite the fact that it fires 12.7mm rounds, and the Chaingun uses a 15mm tungsten slug. Also, both the rifle rounds and Micro Missiles share same ammo despite being obviously different from each other.
 * The Heavy Assault Rifle is an influence from Doom 3 rather than the original Doom, being the equivalent to the third game's Machine Gun. While 2016's Heavy Assault Rifle does relatively more damage per shot than the Machine Gun in Doom 3, the firing rate and accuracy of the two firearms are very similar, and both are called with the number 4 on the keyboard. The two guns fill the role of the Chaingun from the classic Doom series, where as the formal Chaingun in these games is more of a "super" version that only appears later.
 * Because the ammunition of the Heavy Assault Rifle is similar to the .50 BMG round, the Heavy Assault Rifle is like a hand held M2 Browning which uses the .50 BMG round.