They need to lead more. I'm seeing the tracer rounds pass behind the plane. They should be able to hit something, I saw a friend shoot down a bird with a .22 pump.
I think a twin mount 50 Cal M2 qualifies as big...
Whomever the dude was Free handling that MG-42 (MG-3 or M-53) is crazy also.... That sucker had to have had a major rate reducer on it.. I fired 300 rounds through one of these suckers once in a bit less than 30 seconds...