Since those sources say things like “However, the autoloader itself is capable of loading a round and returning the gun to aim on a target of the gunner’s choosing in only 6 seconds if the gunner chooses not to change ammunition types, so the maximum technical rate of fire is actually 10 rounds per minute.” for T-80. The cyclograms cited in the documents even contradict this since they include the time for the “reload” button to be pressed and show this process takes 6 seconds if you make conservative combat ammunition load, ammunition order and count the bloke pressing a button as if that’s relevant to the strict mechanism of the carousel.

T-80 cyclogram.

T-72 cyclogram
T-72 cyclogram at least doesn’t count the time to press the load button, but it does count the time to skip 2 shells which aren’t of the type requested and even counts the time for the cannon to recoil when firing, which it does at 7.4 seconds. These are including other things like cannon elevation to the required reload angle, which again doesn’t happen in War Thunder. In other words 7.4 is the normal/average given combat ammunition loadout, load order and practical facts technically unrelated to the strict mechanism of the autoloader operation itself.
I’m not familiar with this document, it states 8rpm (7.5 seconds) for combat and 7.1 seconds for the next shell in the carousel, which seems in line with what Tankograd’s cyclogram says. Unsure if they are counting the time to press the reloading button or not. Since it’s just a plain number we can’t exactly analyse what is measured. It’s possible combat reloading includes aiming at a new target,we don’t know without further clarification.
I’m curious why Fofanov insists 6.5 seconds though, but I cite Fofanov because it’s a reliable expert source. It’s possible that’s the strict time for the mechanism once the gun is properly elevated and until the new shell is in the barrel, presumably still at reload elevation.
This brings into the point that, as an example, T-72B3 would reload differently since the elevation mechanism is like 15 times faster than earlier models. So is this elevation period considered part of the reload rate?
