XM26 provided two 3-Tube launchers on either side of the aircraft, as well as the necessary sighting equipment. While the XM26 was more of a test platform, the two prototypes were deployed operationally as an emergency measure in South Vietnam to counter the Easter Invasion in 1972. XM29 and the Sagami Mount The XM29 was an experimental door pintle for the main cabin doors of short fuselage UH-1s (at the time the UH-1B/C), for an M60D 7.62×51mm machine gun. The problem with this system was that it could not be used in conjunction with external armament subsystems. Far more common on such helicopters, including the later UH-1F/P/M specifically, was the Sagami Mount, a skeleton frame mount that swung out from a fixed position at the rear of the cabin. This mount was designed for the M60D, but in certain instances, primarily by the US Navy Seawolves, dual M60 machine guns, M2HB machine guns or M134 Miniguns were fitted. Sources debate the origin of the "Sagami" name, with it being attributed to the soldier responsible for its creation, as well as, to the name of the US facility on Okinawa where it was developed. XM30 An experimental system, the XM30 provided fully flexible mounts using the XM156/M156 universal mounts for two XM140 30mm cannon, with 600 rounds of ammunition per gun. XM31 Another attempt to up the firepower from existing systems, the XM31 provided two M24A1 20mm cannon in pods fitted to XM156/M156 universal mounts each with 600 rounds of ammunition, and flexible in elevation only. XM50 XM50 is a designation for the combination of the XM5/M5 and the XM21/M21 armament subsystems, a common configuration used by US forces in South East Asia. M56 A mine dispenser system for the UH-1H helicopter, the M56 is composed of two SUU-13D/A dispensers on the M156 Universal Mount, which is reinforced to handle the additional weight. XM59/M59 A variation on the M23, the XM59/M59 was modified to accept either an XM213/M213 .50 caliber machine gun or an XM175 40mm grenade launcher in addition to being able to mount the M60 machine gun. XM93/XM93E1 This armament subsystem provides door mounts for long fuselage UH-1s (UH-1D/H/N) for two M134 7.62×51mm Miniguns. The USAF also used this system on their short fuselage UH-1F/P helicopters. These weapons are equipped with chutes connected to their ejection ports that directs spent cases and links away from the aircraft. The XM93E1