True that the Lewis magazine is a "pan" but I have never heard anyone call it other than a Lewis "drum", same with the Thompson "drum" magazines.
Sorry, Mike and 44 Amp, but many SMG's are full auto only, including the U.S. M3 and M3A1, the German MP. 28, MP. 38 and MP. 40, the French Modele 38, etc. Aside from SMG designs converted to semi-auto for one reason or another, like the Model 1927 Thompson, there have been a few pistol caliber semi-auto carbines, one notable one being the S&W Model 40 (and wouldn't I love to have one of those!).
Trivia item of the week: Did you know that the model letter for the Thompson SMG magazines, XX, XXX, L, and C indicates the capacity in Roman numerals?