AK74 Bolt and carrier, K-Var $15 chopped off '74 front end special, Romy Kit for the rest of the odds and ends needed. Tapco flat with a 16 guage sheet metal "doubler" bent up and welded over the front half of the receiver. Bbl is one of those CDNN $20 mini uzi bbls.
Bbl was too big in front and too small at rear, so I stuck the bbl between centers on my lathe and turned the front down to fit. Made a sleeve for the chamber area to fit the trunnion. RSB hole was just a little too big, managed to slide some shim stock under it to tighten it up enough. Cut bbl to 16.5 inches when profile was correct.
Receiver was placed upside down in the mill vise and a slot cut out for the drum. I just cut a little at a time, test fitting the drum until it sat high enough to feed properly. One thing I would do differently is cut off the rear rivet area on the front trunnion and shorten up the length of the feed ramp. Milled out a block to make the trunnion solid where the normal mag nose would fit, then milled a feed ramp slot on top to clear the bolt. Long feed length once it leaves the mag but it hand cycles well so far. The rear of the magwell had a "bulkhead" made for it, milled out an L shaped piece. The bottom of the L is tapped for the triggerguard screws and the vertical leg is grooved to hold the guide rib on the drums and stick mags. Still need to make a mag release for it, gonna have to use an SKS type sliding release but hooked to the stock AK paddle to activate it.
Tried hand cycling with the mags held in the magwell, the sticks feed perfectly. The drum is still a little low in the receiver as the bolt overrides the round about half the time. Gonna have to mill the receiver notch a touch deeper to correct.
This is a gas operated attempt, so once I get the mags fitted and secured single shot testing will commence. If all goes well I will drill the gas hole in the bbl and see what happens. If I can't get a reliable cycle using gas I can always plug the hole in the gas block and convert the bolt and carrier to straight blowback.
I had hoped to get some mill time on it tomorrow, but life interferes again. Instead of completing an earth moving job, I got to spend most of the day crawling under a dump truck to fix a leaking tranny line. Looks like tomorrow is earth moving day.