>The firing mechanism of the .50s was not well suited for synchronized firing and lost a lot of RoF while doing so.
You're probably right, but what I'd like to know is the root cause
The time for cyclic operation was obviously low enough for a high rate of fire ... for example, 600 rounds per minute would give a cycle period of 100 ms.
At full engine speed of 3000 rpm (50 Hz), the V-1710 would turn the propeller at half the speed (25 Hz), and with three blades on the propeller, we'd have propeller blades going past the muzzle at 75 Hz. One thing I haven't been able to figure out is whether propeller synchronizers utilized every gap between the blades, or only one per revolution. If it's just one firing opportunity per revolution, as I tend to believe, we'd be stuck at 25 Hz, or every 40 ms.
So this would lead to the sequence ...
0 ms = gun fires
40 ms = gun is cycling
80 ms = gun is cycling
100 ms = gun has cycled and could fire again
120 ms = gun is triggered
Instead of 100 ms per cycle, we'd be up to 120 ms per cycle, but that's a loss of just below 20%, and it would be independend of the type of gun.
Maybe the root cause would be a very slow trigger action? In the above example, there are 20 ms "idle" time before the gun is triggered the second time, and if the trigger action needs 20 ms or less, the synchronizer would actually have been adjusted to trigger a bit early. However, if the free firing gun requires 100 ms for a cycle, but the trigger mechanism needs 100 ms between actuation and firing, then the rate of fire for individually triggered shots would be only have the free-firing rate.
I have no idea if this thought is correct though, and how I could confirm it - I have never seen data on this aspect of gunnery.
I would think that it is desirable to have a fast-acting trigger mechanism in air combat, and I believe the British pressurized air system was designed to provide faster acutation of wing guns then possible with Bowden cables. I have also seen slow initial spin-up listed as a disadvantage of Gatling guns, which is a related issue.
(By the way, years ago there was a neat animation of the synchronization on Emmanual Gustin's site, but I can't seem to find it anymore. If someone had a link to that, it would be highly appreciated!)