3-inch anti-aircraft gun M3
| 3-inch anti-aircraft gun M3 | |
|---|---|
A 3-inch M3 anti-aircraft gun on a M2A2 carriage in firing position with outriggers and crew platform unfolded, preserved in Brazil  | |
| Type | Anti-aircraft gun | 
| Place of origin | USA | 
| Service history | |
| In service | 1928–1945 | 
| Used by | USA | 
| Wars | World War II | 
| Production history | |
| Designed | 1927 | 
| Produced | 1928 | 
| Variants | Anti-tank | 
| Specifications | |
| Mass | Complete: 16,800 lb (7,600 kg) Barrel: 2,302 lb (1,044 kg)  | 
| Length | 25 ft (7.6 m) | 
| Barrel length | 12.6 ft (3.8 m) 50 caliber | 
| Width | 7 ft (2.1 m) | 
| Height | 9.4 ft (2.9 m) | 
| Shell | Fixed QF 76.2 x 585R | 
| Shell weight | Complete: 24.6 lb (11.2 kg) Projectile: 12.8 lb (5.8 kg)  | 
| Caliber | 76.2 mm (3 in) | 
| Action | Semi-automatic | 
| Breech | Vertical sliding-wedge | 
| Recoil | Hydro-pneumatic | 
| Carriage | Four wheel with four collapsible outriggers | 
| Elevation | −1° to +80° | 
| Traverse | 360° | 
| Rate of fire | 25 rpm | 
| Muzzle velocity | 854 m/s (2,800 ft/s) | 
| Effective firing range | 21,000 ft (6,400 m) +85° | 
| Maximum firing range | 8.3 mi (13.4 km) +45° | 
The 3-inch anti-aircraft gun M3 was an American anti-aircraft gun which served throughout the 1930s and into early World War II. Developed from the earlier 3-inch M1917 and 3-inch M1918 guns, it was in the process of being replaced by the time of the US entry into World War II, but was subsequently adapted into an anti-tank gun role, both free-standing (as the 3-inch M5) and in a self-propelled tank destroyer (the M10). It may have seen action in the Pacific Theatre.