One of the original T114 prototypes had a tank destroyer turret for the 105mm recoiless rifle.
It was autoloading from a magazine on the right-hand side. The loading action was interesting, the barrel, with the attached chamber slide forwards, a round slid in from the right and the chamber and barrel slid back, encasing the round until the breech was closed. When it fired, the process was repeated with breech opening, the case being ejected to the rear and then reloading occured.. Rather a complex arrangement but necessary because of the way the US Recoilless rifles worked.
The British developed a similar but different weapon (but I've never seen pictures of it, only read descriptions), with a rotary set of chambers, like a revolver. That was possible because they used the Rheinmetall frangible based case. Each chamber would align with the barrel, slide forward to make a seal and the round would fire. The cylinder would then retract, rotate to the next chamber and the empty case would then be ejected. The Germans used the some principle in their recoilless 20-30mm cannons.
