Guns on a B17

Answer 1

It was a highly successful weapon system, dropping more bombs than any other American aircraft throughout the war. Why was the B-17 called the 'Flying Fortress'? It received this name when the aircraft was unveiled to the public in July 1935 with its massive armament and numerous machine guns. . 

Answer 2

The gun used on B-17s was the Browning .50 caliber machine guns. The number of guns on a particular B-17 depends on its model. A B-17G, for example, has 13 of these guns.