Ive shredded IL2s with a burst from an 8 gunned P-47. I assume all of you have to. Could you imagine doing the same with a 4 gun plane? Oh if your a good enough shot 4 guns is enough, weve all killed fighters with an M3 0.50 . But 8 0.50s is fearsome. 6 is good. And 4 is good enough.
I had a buddy who flew Jugs in Europe and he used knock the snot out of an entire railroad train with his 8 0.50s.
If you're shooting at d500+, odds are you would likely be able with 8, maybe with 6, and on a very very very lucky at conv shot all in the wing with 4.
However, you tuck that range into just over 300, with your convergence set appropriately, 4 50's will shred just about anything.