A.K. drums
I had three Romanian of the type with the loading lever on the front of the drum, rounds were loaded in the top of the mag and you had to push the lever after every round, it was thumbusting, but none of them ever malfunctioned. I know other people that prefer the "chinese type" which load from the back of the drum requiring the rear of the drum to be removed for what I am told is a very tedious and time consuming loading procedure, but I am told they are also very reliable in function.
A.T.I. is marketing a clone of the chinese type, its probably even chinese made, my experience with A.T.I. products is that they are quality products that function as they are intended to.
I have not seen many of the lever loader type drums in the last few years, last one I saw a couple months ago sold for $175, used.