Aircraft guns and their positions

[PMN1]

When did aircraft guns become reliable enough to be able to consider mounting them in the wings?

 

[1635yankee]

Probably about the same time as wings became thick enough to contain them, that is when cantilever wings became de rigueur. I'm not someone with a big interest in guns, especially machine guns, but I suspect that machine guns were sufficiently reliable by the end of WW1.

 

[Scott Kenny]

When did aircraft guns become reliable enough to be able to consider mounting them in the wings?

When there was an air-cooled Vickers gun and the Browning M1919. Then the M2 Browning .50cal in 1924.

But honestly the problem wasn't the guns proper, it was the ammunition quality. All the top aces in WW1 gauged their ammunition in terms of overall length, so that every cartridge was the same length.