| Year | December 1940 |
| Weapon Type | [@type] |
| Origin & Designer | [@designer] |
| Numbers Produced | 20.000 |
| Crew | Sergeant/Squad Leader. Corporal/Gunner. Pvt/Assistant Gunner. 2 x Pvts/Loaders. 2 x Pvts/Ammunition Bearers. Pvt/Driver (Truck). |
| Calibre | 40mm (40x311R) |
| Elevation | -11° to +90° |
| Traverse | 360° |
| Breech | Vertical Sliding Block |
| Recoil | Hydrospring |
| Gun Sight | M3 |
| Gun Mount | [@gun_mounts] |
| Carriage | M2 |
| Trailers | [@trailers] |
| Gun Shield | [@gun_shield] |
| Armoured Plate | [@armoured_plate] |
| Barrel Length | 2.25m (L/56) |
| Overall Length | 5.728m |
| Width | 1.83m |
| Height | 2.01m |
| Weight | Weight in Transit: 2.653kg Weight in Action: 1.981 kg |
| Round Weight | M81A1 (AP) & Mk.II (HE) 2.15 kg |
| Muzzle Velocity | AP 875 m/s. HE 881 m/s |
| Feed | [@feed] |
| Magazine Capacity | [@magazine_capacity] |
| Practical Rate of Fire | [@practical_rate_of_fire] |
| Rate of Fire | [@rate_of_fire] |
| Maximum Rate of Fire | 120 rpm |
| Maximum Ceiling | HE 6.797m |
| Maximum Ground Range | AP 8.557m / HE 9.776m |
| Maximum Range | [@maximum_range] |
| Armour Penetration | 45mm @ 500m @ 30° |
| Traction | 2 ½ Ton Truck |
| Variants | [@variants] |
| Notes | The famous Bofors was tested by the US army in 1937 and was standardize in 1940 and along with the Quad .50 and 37mm, the 40mm M1 was placed in Mobile Automatic Weapons Batteries and held at Corps level under the command of AAA Group. The M1 was towed by truck and were organised in batteries of eight guns. The M1 replaced the 37mm M1A2 as the standard light anti-aircraft gun. |