Anybody know if it works or is convertible?
 

Pretty sure no.   That mag is pretty valuable, no?

Yeah, its spendy.  I really want a drum for my RPK74 though.

Maybe mod a cheap 762x39?

Well, this one came up for $180, so I thought since its closer maybe I could make it work, but further research shows that I'm possibly incorrect.
 

EDIT: Spelling

Upon further research I actually purchased a Polytech 223 drum.

if you are still looking for a 5.45 drum for your RPK 74, there is a 95  round drum on the market.  it's patterned on the BETA CMAG. I bought one last year and it works great in my AKS74U.  

https://www.classicfirearms.com/ak74-95rd-545x39-dual-drum-mag


http://www.hunt101.com/data/500/medium/AKS74U_WITH_95_ROUND_DRUM.JPG





in order to convert a 7.62 or a 5.56 drum to 5.45, you would have to make a new inner "sprocket" to accommodate the 5.45 cartridge . I know this because a couple years back I tried to convert a 5.56 Korean beta drum for the 5.45. the  feed tower no problem, but everything else inside  has to made from scratch.

taking a drum that is the same caliber as the firearm you want it to go on , not a huge obstacle, it's just a matter of installing the feed tower change. but trying to go one caliber to another, you would have to make it from the ground up.  


I've modified  3 drums to fit 3 different gun that drums never exited for. took a  7.62x25  PPSh41 drum  to go into my 7.62x25 PPS43. and taking a 9mm SUMOI drum to go into my 9mm PPS43. and made a 5.56 AK feed tower to go onto my 100 round BETA CMAG FOR MY Bulgarian 106 UR