^-- what he said.
You don't have to add anything but reload delays. There were a number of planes in WW2 that had to manually change drums on the guns, too. The cannons on the Bf110C, for example. The gunner positions on probably half the bombers in the game include drum-fed guns which would have reload delays (albeit only a few seconds in some cases).
The Wirble is a totally unrealistic monstrosity without reload delays. It could fire 20 rounds at a time. That's all it had in the magazine. Staggering the guns (fire bank 1, reload bank 1 while firing bank 2, reload bank 2 while firing bank 1, etc) would slow down the rate of fire but keep the bullets flying. Or they could fire all 4 at once for maximum impact with a delay every 20 rounds per gun.
I think this is one feature that AH really needs, overall, for all planes and vehicles. Just to bring it one step out of the arcade past. In the early days they made a lot of concessions, but IMO in the present time these are no longer needed and we can move on to better standards of detailing/modeling.
