The XM148 is a grenade launcher featured in Battlefield Vietnam. It was designed by American firearms company Colt in 1964. It was an experimental 40mm grenade launcher designed to fit under M16-style rifles. It was designed for field testing in the Vietnam War. It was meant to replace the M79, but had many flaws in its design and was eventually replaced by the M203.
In Battlefield Vietnam, the XM148 is exclusively issued to the MACVSOG and 5th Special Forces Assault kit. It's attached under the CAR-15, but it replaces its ability to aim and increase accuracy with the quick ability to use an under-barrel grenade launcher. It isn't required to switch to the grenade launcher, although this makes aiming impossible. It's a generally welcomed addition to close-quarter situations as the XM148 has a very limited range and an extremely noticeable arc in its trajectory. The inclusion of the XM148 in the Assault kit removes the latter's Hand Grenades.