You have yet to provide any documentation on that. As I said HT doesn't use pilot recollection he uses hard data. Argue with him if you like.
As to your ww adjustments you forgot about being clip fed. 2 gun continuous np quad needs adjustment.
I dont have to prove anything. But I did find what has been presented and it wasnt from a pilot, as from what I read it stated "Govermental Trials" which would implicate testing from another entity. The argument isnt with HT, its with you and your disbelief.
I could not find further information about ROF, I am sure its out there somewhere, but at the low end of 480 RPM that is still alot of lead coming out, does not matter how the gun is loaded, the ROF is the rate at which rounds are coming out of the barrel and not how they are loaded.
Guns in the past that are manually loaded had open feed trays where clipped rounds were dropped into a slot stacked on top of each other and were filled as they were depleted, most AA guns were set up this way for rapid fire and rounds were rapidly fed into this rack to maintain ROF.