I was waiting for decent RPK drum to complete my project for a while now and it finally came out. Ordered it off WGC, paid, got the mag two days after it was shipped out. Here's what I got.
Packaging:
Drum came in packaged in a simple cardboard box filled with bubble wrap with a little sticker on it.
Contents:
Drum mag
Wire with pressure switch
Manual with only pictures on it, no written explanation.
External construction and appearance:
Drum is made out of metal, no plastic parts on the outside. It is not a R/S conversion but manufacturer used decent quality metal. Metal is similar to what TM used in AK dust cover.
Drum is pretty solid, nothing rattles. It only has two moving parts on the outside. Wheel on the back side, which holds two halves together and lever on the front. Not really sure right now why it's there for. Paint job is good too. Almost matching my CA AK47 receiver.
Internal construction:
On the inside drum has three compartments. BB section, battery section, motor and gears section. All sections are separated by plastic dividers but bb's get into all three sections anyways. There was no jams caused by bb's in "non-bb" sections so far.
Loading and operation:
Drum is battery powered, btw no batts included in the box. It uses 4 AA batteries.
Loading techically should take not more than a minute. To load the mag it first needs to be opened. Than, spring powered plastic piece which pushes the bb's up needs to be pulled down until little knob on it goes into a hole in the mag's body and locks there.
After that's done place the batteries into battery section, close the body and hold pressure switch until it's winded up. Just like regular box mag.
Mag performs great, I've tested it with CA AK47 body, fired off couple of bursts and semis. Works good, no misfeeds or jams whatsoever. I will be testing it more during the game tomorrow.
Update: 03/05/06 Used it at the Stargate game last night. Fired lots of shots, don't know exactly how many. No problem with feeding. There was one small problem. Look at the picture, part which is circled broke off because of cold, actaully it's the glue holding it to the metal. So it's a good idea to apply some duct tape there.
Fitting:
That's where I was dissapointed big time. For some reason I think this drum was made to fit TM plastic body (haven't tried it) and CA SLR body (perfect fit but doesn't feed at all).
I've tried CA AK47 receiver and DTP AK47S receiver. Managed to push it into DTP with a lot of force but had no luck with CA. Than, I started filing down excesive metal off the mag but got tired fast, there is
a lot of filing needs to be done in order to fit it. I figured there had to be another solution and after about 15 minutes I found it. I figured since drum holds 3000 rounds it really needs to be loaded once at the beginning of the game day.
So, here's what I did. Loosened screws on the trigger guard, lifted it up a bit, placed the mag into the magwell, tightened the screws. Works perfect

Takes a screwdriver and less than a minute of work.
Pros:
First RPK mag produced in large numbers. Easy to obtain.
Full metal external constuction.
Flawless feeding.
Good price.
Battery operated, no manual winding required.
Cons:
Fitting issues with metal bodies.
BB's inside make too much noise. (can be fixed with some padding I guess)
Hi-cap, probably will not even feed if loaded to a R/S capacity. (personal preference)
Overall, if you really want to have an RPK than go for it, otherwise I wouldn't suggest buying it. I have a feeling that this mag will only be used by me for pics and "run 'n gun" type games at PBall fields.
Update #2: 06/20/06
After approximately 3000-4000 round motor died. Plastic bottom plate pretty much melted. I went to Active Surplus (local electronic store) and showed dead motor to guys who work there. They said that motor is really cheap kind and made for 3V max. It will not survive on 5V (1.25vX4AA batts) for long time. There are two options:
1. Replace the motor with the same kind, which I found for a dollar in that store and wait until it dies again.
2. Install better 9V motor and rewire the whole thing for different power supply.
I got both, cheap 3V motor and good 9V motor. Better motor is a bit larger, I'll try to install it and see whether or not it fits/works.
More pics: