United States 40 mm grenades
The M397 is a pre-set airburst munition, designed to allow grenadiers to engage targets in trenches and behind cover.
The M1060 is a thermobaric cartridge, designed to destroy targets through a combination of intense heat and forceful overpressure (concussion).
The M1060 was developed in order to give grenade launchers a far greater effect against static targets such as bunkers, houses, and masonry.
Also produced was a special 40×53 mm airburst munition for use with either the M75 or M129 automatic grenade launchers, commonly used from helicopters.
Similar rounds have also been developed for weapons chambering the higher velocity 40x53 mm cartridge as well.
Another test variant, the XM576E2, which had twenty-seven 20-grain (1.30-gram) metal pellets without a sabot within the shot cup, was deemed to spread too quickly for effective use.
The only current 40×53 mm type is the M1001, a canister round filled with one-hundred and fifteen 17-grain 2.0-inch long flechettes.
These were developed to penetrate dense canopy foliage in order to mark or signal a position.
[2] In development are new marking cartridges designed to improve the already considerable night-fighting capabilities of US forces.
The XM1062 and XM1065 operate like conventional ground markers, but the XM1062 marks in the IR spectrum, while the XM1065 shows up on thermal imaging devices.
Older cartridges designed specifically for the M79 grenade launcher or the AN/M8 pyrotechnic pistol also remain in inventory.
Intended for use in the UH-1B Iroquois helicopter using the M5 Armament Subsystem, the round was not adopted because of safety concerns.
Testing during 1966 concluded that there were significant reliability issues, as well as, potential environmental concerns (detonation or malfunction from high temperatures and humidity in the South East Asian theater) and increased vulnerability (the WP filler was dangerous if struck by small arms fire).
The parachute slows its descent to 7 feet (2.1 m) per second The similar M583A1 is fired the same way, but illuminates in visible light.
Older cartridges designed specifically for the M79 grenade launcher or the AN/M8 pyrotechnic pistol also remain in inventory.
[2] The M1006 launches a solid foam "sponge grenade" at high enough velocity to wind someone or in extreme cases perhaps even break bones.
The use of a softer foam sponge in the M1006 is likely a product of the serious injuries and fatalities caused by rubber and plastic batons in use by police forces around the world over the last few decades.
Similar systems had been developed independently, and had been used during the landings at Normandy during the Second World War at Pointe du Hoc, but the XM688 allowed an existing infantry weapon to be used in this capacity.
The MK281 uses a patented Rheinmetall propulsion unit that is designed to produce a very low standard deviation in muzzle velocity for improved accuracy.
This tracer has a burn time of six seconds and allows the user to observe the ammunition’s trajectory as it approaches the target.
