The M320 is a single-shot launcher available to the Assault class in Battlefield 4. This launcher can be equipped with various forms of ammunition, though only one is available in a player’s loadout at any given time. The M320 can be equipped as a standalone gadget, or it can be mounted to certain assault rifles using the underslung rail. When using as underslung, the M320 still uses one of the available gadget slots, but switching between the primary weapon and the M320 is faster than if it were equipped standalone. The underslung rail (UGL Rail) is equipped as an underbarrel attachment on ARs in place of special grips.
The M320 HE is the default version of the launcher, available to the player from the beginning of the Battlefield 4 multiplayer experience. This high explosive ammunition is a 40mm grenade with a small blast radius. It is most effective against clustered infantry and light vehicles. It is also effective for triggering destruction, like blowing out walls to reveal hidden enemies. The damage is similar to that of an M67 frag grenade, but the M320 is capable of launching farther than a player can throw. Grenades will explode upon impact.
The M320 SMK (smoke) is unlocked for the Assault at 40,000 points. This unlock allows the player to fire 40mm smoke grenades from the launcher. Upon impact, the grenade releases a cloud of white smoke that is intended to block spotting. The travel arc for the smoke projectiles is the same as that for HE. If an enemy (or friendly in hardcore) is hit directly with the smoke grenade, they can be killed. The smoke grenade is best used to obstruct the enemy’s vision when attempting to cross open spaces.
The M320 Dart is unlocked at 76,000 Assault points. The dart is flechette ammo packed in a 40mm cartridge, turning the launcher into a high-damage shotgun. The dart ammunition flies in a flat trajectory and does not have the range of the HE or smoke ammo. Equipping the M320 Dart as an underslung weapon can be a very effective strategy for clearing close quarters areas within a larger map.
The M320 FB (flashbang) is unlocked at 128,000 Assault points. This ammunition equips the launcher with a 40mm flashbang grenade that temporarily blinds enemies in close quarters to the blast. Like the other 40mm grenades, the launcher allows the player to fire the flashbang at a greater distance than if thrown. The temporary blinding of enemies allows the player to use the flashbang to get a jump on enemies that may otherwise get the jump on them.
The M320 LVG is the last ammo unlocked for the launcher at 155,000 Assault points. The LVG (low velocity grenade) ammunition equips the 40mm launcher with a timed anti-infantry grenade that can bounce off objects before detonating. The LVG detonates after approximately 3 seconds, rather than upon impact. This allows players to use walls and ceilings to reach enemies with a “bank shot”. The LVG ammo does not inflict damage from a direct shot due to the timed fuse.