3-inch anti-aircraft gun M3

The 3-inch anti-aircraft gun M3 was an anti-aircraft gun developed from the earlier 3-inch M1917 and 3-inch M1918 guns which served throughout the 1930s, some into early World War II. By the time of the US entry into World War II, the 3-inch M3 was in the process of being replaced and may have seen action in the Pacific during World War II.

Anti-tank gun

In September 1940 a project started to adapt the 3-inch gun to the anti-tank role, starting with the T9 experimental model but equipping it with the breech, recoil system and carriage borrowed from the 105mm M2 howitzer. The gun was accepted for service as the 3-inch M5.

A similar derivative of the T9 – the 3-inch M6 – was intended to be mounted on the M5 self-propelled gun, which was eventually abandoned. A final adaptation was the 3-inch M7, which included minor modifications for mounting on the M6 heavy tank and M10 tank destroyer. The M7 saw wide use although it was supplanted to some extent by more powerful weapons such as the 90mm M3 and the British QF 17 pounder. A total of 6,824 M7 guns were manufactured.