The .30 Carbine cartridge was a slightly modified .32 Winchester Self Loading, which was never a pistol cartridge.
That's interesting. I never knew that. I need to look that round up.
I think most folks consider it a pistol cartridge due to the round's characteristics; straight wall, round nose, lowish velocity. It looks like a big 9mm.
The round was of course developed specifically for the M1 Carbine and not any handgun.