Ok, I've recently inherited an M-1 30 Caliber...
Being a handgun guy, and never had a rifle before, I've done hours of research to find out how the .30 Caliber round relates to 30-30 and 30-06.
Kinda happy to see that a number of you dealt with the often abused "Caliber".
Too often we see that word used when "cartridge" is what is meant.
.30 caliber rounds....A quick check in Cartridges of the World shows at least 40 different cartridges all of which are .30 caliber rounds. (Not even counting the wildcats developed by Elgin Gates).