The XM307 Advanced Crew Served Weapon (ACSW) was a developmental 25 mm belt-fed automatic grenade launcher with programmable airburst capability.

As a part of the Small Arms Master Plan (SAMP) program, it is intended to either replace or supplement the Mk19 automatic grenade launcher and the M2 heavy machine gun.

It fires 25 mm point-detonating and air burst style ammunition, including HE, and HEAT at a cyclic rate of 260 rounds per minute and has an effective range up to 2 kilometers.

The XM307's airburst rounds make it much easier to bypass walls protecting enemies that could cause collateral damage if fired upon directly.

Operators do not have to shoot through the wall, just through an opening or over the top to kill the people behind the cover, leaving the structure of the building intact.