I, unfortunately, must disagree with my squadie. I was flying in a P-51 today, (By the way, i haven't seen many of the squad members on) and i shot an F6F with only 50 rounds from my 50. cal and it blasted the wing away. I would prefer [2000] .303, than [850] 50., and [310] 20mm.
Why? Proof... I was flying an Mk I Spitfire and i managed to (unbelievably, i got VERY lucky not being noticed) put 200 .303's into the cockpit and engine. Plane went down, if you remember me, I'm sorry and good flying!