I’ve seen drums for sale, but I’ve never actually known anyone who uses them.
I've got a 75 rd drum for my Romanian AK-47. Loaded it and tried it out. Now it sits and waits for a reason.
Because most of them suck. Chinese pattern AK drums are GREAT and so are 20 rounders for my saiga 12. Tommy gun drums are heavy and jam a lot, a KP31 I rented once was comically heavy, like 25 pounds for an SMG. My roommate runs a 100 round AR drum and I’ve never seen it jam, never used it myself.
The thing to remember about drums for pistol calibers is that the rounds inside them can fall over and cause some pretty gnarly jams. I had all kinds of fun unjamming the M1927 under spring tension.