You know, that is a cool idea. With the thin base of the carbine round, I could see it making a handy drum that isn't too big at all. Now you've got me thinking... and I don't even have an M1 Carbine... yet
There was one at the last gun show. It was a mere $350 or maybe as low as $300, I forget which... But it was a Universal. Now I've saved a Uni and could save this one too. It also comes with a Choate Pistol grip stock, my preference actually. It's a whopping deal with that stock, but I haven't been able to justify a carbine since AKs are cheaper and shoot a cheaper and more powerful round. But I might just have to get this one and build drum for it.
One thing that would be cool is an X39 Saiga with the standard stock, 20" barrel, and a drum. It would be harder to make US compliant than the standard P-grip conversion, but holding it that high with the drum so low would really balance it out, at least I would think so. I think someone on Saiga-12.com or Gunsnet did that to a 16" one.