The XM25 is a gadget available to the support class. By default, it is available with 25mm airburst grenades as a starting gadget. The launcher is outfitted with an IRNV scope. The XM25 is a semiautomatic weapon, which uses a 5-round magazine. In Battlefield 4, a player is able to carry three magazines at a time, or 15 rounds, of whichever XM25 ammunition is selected.
The XM25 is available with smoke grenades once a player has accumulated 63,000 as the support class. The XM25 Dart is unlocked at 119,000 accumulated support score. The different ammo types of the XM25 are equipped as separate gadgets. The XM25 can only be in one gadget slot, thus a player cannot equip the various ammo types at the same time.
To use the XM25 as an airburst grenade launcher, a player points at a surface that is the distance at which they would like to fire within a maximum distance of approximately 300 meters. To lock the distance, the player aims down sights at the surface with the aiming reticle. If locked, the scope will say LOCK in red letters at the bottom of the scope display. If no lock is attained, the display will instead be a red N/A. At this point, the right side of the scope display will indicate the distance in meters to the surface at which the player is currently aiming next to the red RNG. The airburst offset (OFST) is three meters. This is added to the locked range for the final airburst (ABRST) range. If a player locks on to a ledge 100 meters away, the final airburst range will be 103 meters, meaning the grenade will travel 103 meters before bursting mid-air. This function is what allows a support player to damage enemy players just beyond cover. When hip fired or fired ADS without a lock, the XM25 grenades detonate on impact. One of the most frequent uses of the airburst grenade launcher is to damage or kill enemies just around a corner, or snipers hiding on a roof.
When equipped as the XM25 Smoke, the launcher operates in the same manner as the grenade launcher function, including the ability to lock to a particular distance and airburst three meters beyond the locked distance. The smoke grenades, whether fired in airburst mode or impact burst, will create a small field of smoke that begins to dissipate after approximately 3 seconds, and will completely vanish after about 5. Smoke grenades can kill enemies with direct impact. Because of the flatter trajectory of the launcher, the XM25 allows for placing smoke with precision from longer distances.
Equipping the XM25 Dart provides a player with a 5-round semiautomatic shotgun with Flechette ammo. Because it is the XM25, the Dart is equipped with an IRNV scope by default, providing a slight advantage over other shotguns in darker areas. Being semiauto, it can be fired rather quickly, but is limited by the 5-round magazine. It is a one hit kill in close quarters, but damage drops off quickly between 10-20 meters. The XM25 Dart allows a player to still carry an LMG, while also carrying a shotgun equivalent for close quarters encounters.
Please see the following video for a visual guide on using the XM25′s range locking airburst feature: