Developed by General Dynamics, the XM 307 ACSW (Advanced Crew Served Weapon) is “intended to either replace or supplement the Mk19 automatic grenade launcher and the M2 heavy machine gun.” Video demonstration after the break.

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