General: Bunch of Post WWII tanks of the Bundeswehr
The Europanzer project, in 1955 the first try of post WWII germany to build a tank in cooperation with France (yes the same france we invaded and occupied only 15 years earlier). One of the first Standardpanzer (engl Main Battle Tank) prototypes, more specifically Prototyp I B, you can clearly see the resemblance to the later Leopard. This tank has a 105mm semiautomatic main cannon.
So now I do have some proper info about the weapon on the Standardpanzer Prototyp I B. And damn that thing is insane.
The gun was developed by Rheinmetall as a competitor to the British Royal Ordnance L7 105mm rifled tank gun. Even though Rheinmetall suggested a smoothbore cannon, something like that didnt exist yet and thus they decided to go with a rifled 105mm tank gun.
Now to the interesting part, as it was a joint development with france they had access to the insanely powerful OCC-105-F1. http://www.kotsch88.de/m_105mm-m57-2.htm
I dont know who figured out how to stabilize that thing but damn thats some impressive engineering right there. And the best part? 360mm or RHA at 90°.
That gun however was never mounted into the vehicle.
Actually screw that, despite a lot of people and Internet posts saying both German Europanzer Prototypes should have a 105mm cannon u/Strikaaa just found a source that says they still had the BK 90
Okay, I got it now. I hope.
Both tanks were intended to field a 105mm rifled tank gun, however when the prototypes were built neither gun was ready/available. Thus they fitted both vehicles with the BK 90. Thats according to source one. https://imgur.com/a/A6dX0
Thats why the gun in the pic above looks an awful lot like a 90mm. Because it is.
Now according to source two https://imgur.com/a/4aNpV for the final trials the I A prototype (the pic below in which the L7 is clearly visible) was fitted with the L7 so that the tank could be tested in its final and intended stage, Rheinmetall however determined to produce a auto loading 105mm tank gun from scrap didnt have their product finished yet.
In the end however the L7 was approved because it was available en masse and because then more NATO countries would use the same gun.
Cant tell you anything about the loading system though.
-4 man crew
-max speed 63km/h
-main weapon [105mm semiautomatic Rheinmetall cannon] intended, 90mm BK 90 actually fitted both with optical rangefinder
-secondary weapon 2x MG3
-armor Front - 50 mm / Sides - 25 mm / Back - 15 mm / Turret - all around 60 mm