Now, for the Germans. Thankfully, British trials (WO291/1003 Motion studies of German Tanks) left us a plethora of materials on testing German trophies in the most minute details. Let's take a look at one of their tests, that of the Tiger.
As you can see, the sequence of actions is quite limited and only involved retrieving the round from the ammunition rack and placing it into the breech. No extraction or firing is performed. Here is the full spectrum of loading trials:
Loading the first four rounds takes about 7-8 seconds each in the more favourable positions. Very few rounds can be loaded in a sliver under 6 seconds. As the loader uses up the shells that are closest to him, the amount of time needed to load a shell increases drastically. Based on this information, can you guess that the rate of fire of the Tiger was recorded as?
10 RPM. It appears that the data was extrapolated from the loading of a single shell in optimal conditions, something that in no way represents the rate of fire of a vehicle in combat.
Conveniently, the rate of fire for the Tiger II is right there, so let's take a look at what the British discovered. These are tests of the ready racks only, the ones that are most readily accessible.
Even from the best of racks, the long shell of the KwK 43 made loading the gun a difficult chore. You can see that it takes 8-10 seconds to load a shell, resulting in a maximum theoretical rate of fire of 6-7.5 RPM. In Soviet trials, the Tiger II scored a maximum of 5.7 RPM, which is reasonable, considering the addition of the extra overhead of actually firing the gun. However, as you can see from the above table, the Germans gave their Tiger II a rate of fire of 6-10 RPM, significantly higher than practical trials suggest is actually possible.