Nowadays? "A Machine"
In previous times? "a weaponsmith", "a gunsmith".
Gatling guns ,cannons
Tanks use cannons; and aircraft use machine guns or automatic cannons (small caliber such as 20mm, 30mm, etc). Tank cannons are called "main guns." During the Vietnam War, the US Patton tanks fired 90mm main guns; while the Australian Centurion tanks fired 84mm guns.
Hand guns and long guns, cannons
The original Focke-Wulf FW 190 had 6 guns - 4 20mm cannons and 2 13mm cannons.
They used cannons and other types of guns.
The big guns, cannons, mortars.
A person who makes and repairs guns
Get some cannons and automatic guns
guns and cannons
Guns and cannons
A gunsmith makes and repairs guns.