well like I said, I think it would be tough to pull off in a MG only bird. Do you have a screenie one of these too-many-times-to count passes?
I think it would look cool.
No because I never film but I'll try to get one over the weekend.
As a practice there are two efficient methods of getting three on a single pass.
The first is to pull alongside the buffs and slightly above about 2K off their wing. Roll into them and as they continue forward you will come in aligned with the drone and the lead buff. Take the drone and the lead in-line, then turn for the final drone.
The other way is a little more dangerous. Come in from almost co-alt six crossing slightly from right to left to force the gunner to lead. Take the left wingtip of the left drone first then align on the right wingtip of the lead buff. As you do the right drone will cross across your gunfire as it moves to the left giving you near simultaneous kills on the drone and the lead buff. Obviously, if the guys a good gunner this one's tough as it requires you to reduce closure rate and sit in the gunfire for a few moments... not for the weak of heart. The caveat is that as the right drone moves across the lead buff guns get temporarily interrupted so if you get that far you're golden.