US Army’s Armament Center researchers have invented novel 40mm grenade cartridges capable of kinetically disabling or destroying small UAVs. The development is made up of two actions. The first 40mm cartridge fires shotgun-style buckshot from a newly designed cup, the second fires a stack of aerodynamic rings. US Patent 10,584,947, issued to the Army on March 10, 2020, describes the sub-projectile carrier developed by the engineers to control the spread of the buckshot BBs, which extends the maximum effective range of the munition. U.S. Patent 10,408,591, issued to the Army on Sept. 10, 2019, describes the munition containing six ring-shaped projectiles, which spread out to cover a large area and can create punch holes in the UAVs.