Oh honey, that person is called a gunsmith or an armorer. They're the ones who put together those weapons that go bang and boom. Just don't go calling them a "gun maker" at a fancy dinner party unless you want to raise some eyebrows.
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
I think the word you may be looking for is "artillery". Artillery pieces are larger than small arms like handguns or rifles. They include cannons, mortars, and howitzers.
A gunsmith makes and repairs guns.
Get some cannons and automatic guns
No
guns and cannons