The M319 Individual Grenade Launcher, more formally known as the Individual Grenade Launcher, Caliber 40mm, M319, is a single-shot, break-action explosives launcher used by the United Nations Space Command, specifically the UNSC Army. Due to its simplicity, ruggedness, and firepower, it has been a mainstay weapon in the UNSC Army since its adoption in 2263, and has seen action in several armed conflicts during nearly three centuries of use, with the Human-Covenant war as the most prominent. It saw use during the Fall of Reach.
The grenade launcher has two firing modes. The first launches a single grenade: after hitting a surface, the grenade detonates on impact with an opponent or after the time of a frag grenade's detonation, in which case the grenade will explode after bouncing off the ground once. The second firing mode shoots a grenade that explodes when the player wishes. This is performed by holding down the trigger, which fires the grenade but merely primes it; it will only explode after the trigger is released. This enables the player to lay a trap if the grenade is bounced properly into position, and essentially creates an explosive with a dead-man's trigger (a trigger that will go off once it is released, e.g. when the player dies). This function is also helpful if the player wishes to fire at targets that are farther away than the detonation timer would normally allow. This firing mode also generates a small EMP field from the grenade when detonated, which can be used to momentarily halt vehicles or remove personal shielding. Like the fragmentation grenade in Halo: Reach, a player will take damage if hit by the grenade when it is merely primed.
The IGL also has a tracking function which is useful when trying to target enemy infantry or vehicles that are fleeing. As long as the enemy is in range, and the targeting reticle is red (which is the indication of in-range enemies), using either firing mode will ensure a hit as long as the cursor remains on the enemy at all times, as the grenade will track the target.
This tracking function is especially true and especially useful for the Falcon variant in the Campaign level New Alexandria that possesses an IGL turret—the range is extended quite extensively and a player can shoot down Banshees using either the explosive grenade (which can literally track a Banshee across the level just like a target-locked SPNKR missile) or the secondary EMP blast that makes them plummet helplessly towards death.
The IGL's target-locking ability is much like the targeting mechanisms for both the Plasma Launcher and the Rocket launcher, however the handheld IGL has a much shorter range than the respective heavy weapons, yet the grenades can easily be bounced in precise angular measurements to ensure lethal shots. The IGL turret, however, with its incredibly high rate of fire and debilitating power, has a higher potential for lethality and also retains the original aspects of the handheld grenade launcher—both manual and automatic detonation and the grenades are capable of bouncing in tactical angles to eliminate singular or multiple enemies.
The Individual Grenade Launcher is a weapon of potentially high lethality, as even in the hands of unskilled players it can be effective. It is believed to be more difficult to use than a Rocket launcher, however, yet the two weapons retain the same potential for causing "splash" damage that is capable of eliminating multiple foes. In a skilled player's hands, the Launcher can be a perfect tool for crowd control, especially when used in certain areas such as the spawn points in the Firefight maps Holdout and Glacier. As the IGL basically delivers modified frag grenades, the grenades themselves are similar to the regular Fragmentation Grenade in terms of both physical dynamics as well as the properties of explosive splash damage that can effect a single enemy or a group of enemies. Overall, this weapon can be a valuable asset, both used as part of a team or when playing solo, as it is one of the best weapons to use to dispel crowds and clusters of foes.
- The IGL is very versatile, allowing it to be used for a number of operations—even quick reflexive counterattacks—and has an enormous potential for the destruction of both vehicles and enemies (Spartans and Covenant alike).
- The secondary EMP fire makes it easier to hijack vehicles (especially useful against aircraft or slow-witted tank drivers).
- Rate-of-fire-wise, the IGL can utilize even more EMPs than the Plasma Pistol (3 seconds of reloading between each shot versus 2 seconds to charge up and 4 seconds of cooldown after said shot).
- Players skilled with it can be a deadly force. A direct hit with a grenade will always kill another player instantly. If the player is good at "leading" his/her target, this weapon can be even deadlier.
- It holds quite a large max load of sixteen grenades, which can compliment the default 2x Fragmentation Grenade spawn count very well, putting up to eighteen grenades at a player's disposal.
- Weapons such as the IGL offer the ability to ignite other hazards nearby, such as fusion coils, nearby grenades (both Plasma and Frag), dormant and damaged vehicles, etc. In some cases it is possible to actually blow a nearby vehicle up and have it land on or nearby an enemy, resulting in a Splatter.
- When used in tandem with other heavy weapons, or even with other players using the IGL, it can be an excellent method to quickly wipe out an opposing force.
- It can be used to set traps, as the grenade will not detonate if the trigger is held down, and the grenade itself can be hard to spot.
- The IGL can be quite difficult to use, and can take quite some time to get used to for some players. Accidents can happen very regularly with the IGL if one is not careful, as the grenades can bounce off of any object—whether it be a weapon on the ground, a crate, an angled doorway, etc.
- The secondary EMP function of the IGL affects even friendly players, and can inhibit teammates when an EMP blast hits their teammates' vehicle, knocks out their shields, or perhaps ignites a nearby grenade, resulting in an accidental betrayal.
- If "Friendly Fire" damage isn't turned off in a multiplayer Firefight game, using the IGL can cause severe ruination to a team as it is quite easy to betray a nearby player and dwindle the precious pool of lives.
- There are few situations in the campaign wherein this weapon is the best choice, as every function it has is performed better by other weapons. The explosion from the round is weaker than a normal frag or plasma grenade, and much less powerful than a rocket. Also, the EMP is not strong enough to knock out even an Elite Minor's shields on normal difficulty, which a charged plasma pistol shot is easily capable of. Also, its limited ammunition, lengthy reload time and the fact that a charged grenade is uncontrollable while in flight makes it difficult to use and unsuitable for most encounters.
- When fired normally (without holding the trigger), the Grenade Round makes a quiet whistling in flight. When the trigger is held, however, the round will make a noise remarkably similar to a tea kettle whistling, possibly as a gameplay strategy to alert attentive players to its presence.
- The Grenade Launcher has multiple nicknames among the fan community and Bungie alike, including "pro-pipe", a reference to the numerous grenade launchers in first-person shooter games, which have been collectively dubbed "noob-tubes".
- The M319 IGL, having been developed in 2263, is the oldest known active service weapon utilized by the UNSC.
- In the Beta, if a player fired the M319 and held the trigger until he/she died and someone else picked up the weapon, the player holding the M319 would take control of the dormant grenade.
- The M319 bears a very close resemblance to the real-life Russian GM-94. However, their similarities are merely aesthetic, as the GM-94 is a magazine-fed pump-action grenade-launcher using 43mm grenades. The M319 also bears a close resemblance to the American Springfield Armory M79 grenade launcher in both aesthetic and functional fronts. The two are break-action launchers that fire 40mm shells.
- When reloaded, the M319's operator does not extract any empty shell casing. This could mean that it uses a caseless grenade round.
- The grenade has a very poor trajectory, traveling only 100 yards before hitting the ground (real grenade launchers can travel approximately 430 yards).
- In the alpha build, the M319 has a red light on its side. This was removed later in the beta build, and re-appeared in the retail version when the grenade detonated.
- The counter on the left of the weapon switches from "ARMED" to (very briefly) "LNKNG" just after launch, and then to either "IN AIR" or "LINKED" after the round is launched, depending on the firing mode; and finally to "BOOM!" upon detonation.
- The Grenade Launcher's reticle maxes out to 35 degrees above and below the horizontal level, totalling both results in a total angle of 70 degrees, possibly a reference to the number 7.
- Sometimes if you kill an enemy in campaign with the Grenade Launcher your allies may compliment you saying words like "nice throw" as if you killed the enemy with an actual grenade throw.
- If a player fires the IGL in EMP mode that comes near an enemy or group of enemies the number of enemies near the grenade is displayed on the counter as an x1, x2, x3, etc. next to a skull and crossbones. This proximity sensor allows the user to know how many enemies are in the blast radius of the grenade. This is can also be used to make the grenade a small mine, and allows the "mine" to be effectively detonated, even if you don't have a good line of sight.
- The IGL can also be used as an improvised mortar, much like the Halo 2 Brute Shot, this tactic is ineffective at best and is mostly a trick shot to use in Firefight, (you don't get medals for it, but it's still a lot of fun to try!)
- If the "bottomless clip" setting is activated, the M392 will function identically (gameplay-wise) to the MG460 MGL found on Falcons.
- It is possible to launch a grenade into a lift and detonate it when it reaches the top. This can foil the would be camper looking for assassination medals.
- In Halo 5: Forge game files, a nearly-complete Grenade Launcher can be found including animations, sounds and a finished model.