Battlefield Wiki
Battlefield Wiki

An underslung rail in real life.

An underslung rail allows weapon accessories to be attached to the underside of a firearm. Many accessories such as foregrips, bipods and flashlights are compatible with rails.

Today there are many different rail-systems, like the NATO standardized M1913 "Picatinny" rail or the older, and partly compatible Weaver-rail.

The rail was implicitly used in Battlefield 2, Battlefield 2142, and Battlefield: Bad Company 2 for their respective assault rifle attachments.

Battlefield 3[]

"Used to attach underslung grenade launchers and shotguns. Without it, these weapons will be equipped stand-alone."

— In-game description

The Underslung Rail is an attachment featured in Battlefield 3, available for most assault rifles. It allows either the M320/GP-30 or M26 MASS to be mounted to the rifle instead of being used standalone, decreasing the time needed to switch between the two weapons. Any optics mounted to the rifle can also be used with the underslung weapon, though the M26 benefits more from this property. The rail is not available on any of the bullpup style firearm except the AUG A3.

While using the underslung weapon, the soldier carries the weapon in a manner suggesting its use. M320/GP-30 users will tilt their weapon back, while M26 MASS users will flip out the weapon's left-hand bolt.

If a Medkit is selected, the rail will have no effect whatsoever. Also, certain combinations of weapons cannot be mounted together:

Battlefield 4[]

"Used to attach the M320 or GP30 Grenade Launcher in the underslung position for faster application of 40mm grenades."

— Battlelog description

The UGL Rail (Underslung Grenade Launcher rail) is an attachment featured in Battlefield 4 as a way to mount certain gadgets to assault rifles.

Unlike in Battlefield 3, players have the option of not mounting any underbarrel accessory, leaving the slot vacant and forcing the user to use the M320 or M26 MASS as standalone weapons.

The FAMAS, ACE 23, F2000, and Bulldog remain the only assault rifles unable to mount the UGL Rail.

All UGL rail capable rifles can attach the Grenade Launcher; however, only five rifles can mount the M26 to the UGL rail: SCAR-HM416M16A4, CZ-805, and AR-160.

The UGL rail is bugged in BF4 when using a Commander Resupply Crate, especially the one in Test Range. The launcher functions in standalone form, separated from the assault rifle. Redeploying in Test Range will allow the UGL rail to function properly.[1]