M4 autocannon
| 37 mm Automatic Gun, M4 | |
|---|---|
| Type | Autocannon |
| Place of origin | United States |
| Service history | |
| In service | 1942–1945 |
| Used by | United States Soviet Union |
| Wars | World War II |
| Production history | |
| Designer | John Browning |
| Designed | 1921–1938 |
| Manufacturer | Colt |
| Produced | 1939 |
| Variants | M9, M10 |
| Specifications | |
| Mass | 213 lb (97 kg) |
| Length | 89.5 in (2.27 m) |
| Shell | 37×145mmR |
| Caliber | 37 mm (1.46 in) |
| Action | recoil operation |
| Recoil | 9+5⁄8 in (245 mm) |
| Rate of fire | 150 rpm |
| Muzzle velocity | 2,000 ft/s (610 m/s) |
| Feed system | 30-round magazine |
The 37 mm Automatic Gun, M4, known as the T9 during development, was a 37 mm (1.46 in) recoil-operated autocannon designed by Browning Arms Company and entered service in 1942. The M4 and its variants would primarily be manufactured by Colt's Manufacturing Company and Oldsmobile (under-contract by Colt) and is therefore sometimes referred to as the "Colt M4" or "Oldsmobile M4." It was primarily mounted in the Bell P-39 Airacobra and P-63 Kingcobra, with the U.S. Navy also using it on many PT boats.