High Quality Content by WIKIPEDIA articles! The XM307 Advanced Crew Served Weapon (ACSW) was a developmental 25 mm belt-fed Grenade Machine Gun with smart shell capability. It is the result of the OCSW or Objective Crew Served Weapon project. It is lightweight and designed to be two-man portable, as well as vehicle mounted. The XM307 can kill or suppress human beings out to 2,000 meters (2,187 yd), and destroy lightly armored vehicles, watercraft, and helicopters at 1,000 meters (1,094 yd). The project was canceled in 2007.