I believe that I indicated in my first posting that I was talking about 4831 released by Hodgdon which he had purchased just after WWII. We used to buy it in 100# kegs for $50.00. When it arrived, we would bring our own containers and divide it up. I used in 30-06 and 30 H&H. After the surplus powder was used up, I believe that Hodgdon and other manufacturers sold different versions which were similar to but not exactly the same as the surplus powder and that the various "4831's" differed slightly from manufacturer to manufacturer. I am not familiar with these 4831's as I never used them.
I have not fired an Oerlikon in about 70 years but as I remember it, the gun fired from an open bolt. It had a very strong spring and to cock the gun we used about a three foot lanyard with an "eye "on each end. You would elevate the gun to maximum elevation, slip one eye over a boss on the mount and the other to the cocking knob . The cocking knob was above the elevation pivot so that when the gun was raised to the horizontal the gun was cocked. It had a double loading stop that prevented a second round from trying to enter the chamber when there was one already there.
The drum magazine held 60 rounds and had a handle on the rear. To load, the lip on front of the magazine was engaged first, and the magazine was closed to the rear where it was latched. To reload, there was a spade type of magazine release that was operated by bringing your had forward to slap the release and letting it continue on to grab the released magazine by the handle. Using the handle , the magazine was removed and a new one loaded.
There was a version where the gun could be raised or lowered using a wheel to operate a hydraulic piston. The idea was to keep the gunners knees slightly bent. The problem was that during cold weather, only a gorilla could turn the crank.
The gunner strapped himself into to "U" shaped shoulder pieces and was strapped in. He had two handles. The trigger was a crank shape item on the right grip, pulling this to the rear fired the gun.
I doubt that 50 caliber ammo was loaded with 4831, but that's my opinion.
FWIW