I recommend Russian RPK drum or a copy. There is a chinese type drum as well but I prefer the Russian design.
Chinese drum is flat disk design whereas the Russian design is concave/convex. That means that the rounds in the magazine follow similar curved route as they do on the ordinary double stacks. Russian magazines are very reliable after setting them up.
I googled a bit and found a site with pictures of both variants:
There are Chinese pattern drums, that are made in Europe (Bulgaria and Romania?) when i had the same problem trying to decide what if any drum i would get, the end result of my study was that the Chinese type is vastly superior to the Russian design. These can be had for 80€ + delivery from German surplus (ex-DDR surplus, unissued…) online stores and i think some will ship also to USA (if legal?).
I got a couple of the Arsenal Bulgarian chicom style (rear loading) drums. The advantages of the chicom type is you can load them whenever and not wind them up and they are WAY easier to load since the back flips open. The chicom style aren’t are robust as the Sov (top loading) style and neither is a dummy proof as AK or RPK box mags. The chicom type drums are also noisy as the rounds slap back in forth in a metal box.
That said, I bought my drums for under $100. I would just get more 30 or 40 round mags if the drums are running more than that.
Be advised, they are loud during movements (they rattle quite a bit) but have had far more problems with Russian/Rommy drums. Better suited for fixed defensive positions than active/offensive IMO.
I have used the Chicom and had zero issues with it. Here is a youtube video on loading a drum. The directions that came with mine looked like someone had taken a bat to Google Translate.
From personal experience during the 90s…
The Russian drums seemed more reliable than the Chinese drums.
But, the Chinese drums were easier to load and were less expensive than the Russian drums (you could buy 2 Chinese for the price of 1 Russian).
Drums are bulky, heavy and noisy. I only used them when static or at the range.
What I would like to know…
Does anyone have any experience with the Korean drums?
They are a copy of the Chinese drum and can be had for around $90(pre-panic).
From my personal experience as an Advisor to the IA- both patterns rattle, but when you need to bust a move with the Chinese Drum, and both spring clips manage to undo themselves, you’re going to be one unhappy dude with 75 rounds spilled at your feet.
This is not an issue with the East Bloc pattern drums.
Also, the ability to wind the Chinese drum means the ability to improperly tension the spring. There is no issue whatsoever with leaving either drum loaded under tension, and you would have to work very hard to wear out the spring.
You’d be far more likely to render your drum inoperable by dropping a loaded drum and denting the body than ever wearing out the spring.
All that being said, I’ve used both types recreationally, and the Chinese pattern is nicer to load.