They made AR tower AK 5.56 drums for a year or so. Very rare, and run like *&$#&.That said, the 7.62*39 guts from a Romy mag should fit one. Getting the 7.62 floorplate to clear the tower might take some doing.
about 10 or so years ago, soon after I bought my SLR-106u (5.56) AK, I modified a BETA 100 round drum AR feed tower to go in that AK.
by cutting the top portion off the AR feed tower, then cut the top portion off from a plastic TAPCO GAILIL/GOLINI mag. then I matted the 2 pieced together using J-B WELD and 2 aluminum braces.
it's still solid as Rock of Gibraltar

and functions perfectly
the problem was that you can't load those drums by hand, spring tension is way toooooo tight for that. so I modified a BETA stripper loader to go over the AK. now I can load the drum easy and quickly
I'm probably the only one if the country that a has a 100 round 5.56 AK drum in the country

at least I have never seen one on the boards
since I made that, I went on to make a 70 round drum for my 7.62 and 9mm PPS 43 using SUOMI and PPSH-41 drums and 70 round drum for my MP5k and they all function perfectly, because that's how I roll
for those interested a video of me loading that 100 round AK drum and shooting
https://youtu.be/SMiFz9spQXg