Yanks and their MG's

[whatnot]

One thing I've found curious the deeper I've gone studying the fighter development from 1930's forwards is that why did the US stick with 50 cals as their weapon of choice on fighters for so long?

I'm no über-guru in the topic, but during WW2 for example the only cannon I find is the hispano in P-38. Then even going to the jet age P-80 and F-86 both had MG's until F-86 H model.

So was it the high rate of fire, smaller weight, logistics of the ammo, the lack of bombers to shoot down or didn't they just get the advantages of a bigger caliber until later?