37 mm gun M1

The 37 mm gun M1 was an anti-aircraft autocannon developed in the United States. It was used by the US Army in World War II.
The gun was produced in a towed variant, or mounted along with two M2 machine guns on the M2/M3 half-track, resulting in the T28/T28E1/M15/M15A1 series of multiple gun motor carriages.
In early World War II, each Army Anti-Aircraft Artillery Auto-Weapons battalion was authorized a total of thirty-two 37 mm guns in its four firing batteries, plus other weapons.
During World War II, the 37 mm gun M1 was deployed in Seacoast defense in [the United States|coast defense] anti-motor torpedo boat batteries alongside 90 mm guns, usually four 90 mm and two 37 mm guns per battery. Some AMTB batteries consisted of four 37 mm guns, but most sources have little information on these batteries. In the later part of the war, the 37 mm gun was typically replaced by the Bofors [40 mm Automatic Gun L/60|40 mm Bofors] gun M1.

Components

One or two gun units were coupled to the M5 gun director using the M1 remote control system. The system was powered by the M5 generating unit. If the remote system was inoperative, the M5 sighting system was used, but it was only usable up to 25 degrees of elevation.

Ammunition

The M1 utilized fixed ammunition. Projectiles were fitted with a 37×223mmSR cartridge case.

Type	Model	Weight	Filler	Muzzle velocity	Range horizontal/vertical
APC-T	APC-T M59A1 Shot	1.44/0.87 kg	-	625 m/s	5,290/3,660 m
HE-T	HE-T SD M54 Shell	1.21/0.61 kg		792 m/s	8,275/5,760 m

Ammunition / Distance	457 m	914 m	1,371 m	1,828 m
APC-T M59A1 Shot	23 mm	18 mm	15 mm	13 mm
APC-T M59A1 Shot	25 mm	18 mm	15 mm	13 mm

Variants

The 37 mm M9 autocannon was a derivative of the M1A2 anti-aircraft gun. It had a barrel, weighed , had a muzzle velocity of, and had a rate of fire of 150 rounds per minute. It was used on PT boats around 1944 in the Pacific theater during World War II, replacing the M4 autocannon.