It looks like a variant of B-10 rocket.
The
M40 recoilless rifle[17][18][19][20] is a portable, crew-served 105 mm
recoilless rifle made in the
United States. Intended primarily as an
anti-tank weapon, it could also be employed in an
antipersonnel role with the use of an
antipersonnel-tracer flechette round. The bore was commonly described as being 106 mm
caliber but is in fact 105 mm; the 106 mm designation was intended to prevent confusion with incompatible 105 mm ammunition from the failed M27.
[21] The air-cooled,
breech-loaded,
single-shot rifle fired fixed
ammunition and was used primarily from a wheeled ground mount. It was designed for
direct firing only, and
sighting equipment for this purpose was furnished with each weapon, including an affixed
spotting rifle.
Ontos M50A1 with six 106 mm M40 recoilless rifles
A limited number of
M50 Ontos were built as a self-propelled light armored tracked anti-tank vehicle. They had six 106 mm M40 recoilless rifles as its main armament, which could be fired in rapid succession against a single target to guarantee a kill.
Replacing the
M27 recoilless rifle, the M40 primarily saw action during the
Vietnam War and was widely used during various conflicts thereafter in Africa or in the Middle East. It was replaced by the
BGM-71 TOW anti-tank missile system in the US Armed Forces.