I suspect this is one of those subjective questions. Here where I live in LA, we didn't have a deer season until the 60's as the WT was virtually non-existent until then. I started hunting in the late 60's and by far the most prevalent cartridge of those I know/knew about was the 30/06. Yes-there were a few 30/30's but around here I didn't know of anyone who shot a Savage 99 in one of it's iconic chamberings.
This was kind of my experience as a kid/teenager in the 50s and 60s. Most of the younger to middle-aged men that hunted the few deer we had were WW 2 veterans or closely associated with them. They had learned to like the .30-06. Probably over half though hunted with shotguns. As you say, there were a few .30/30s. Our family moved to Northern Utah in the late 60s for a few years and there without question the .30-06 predominated. But I would say nationwide that the .30/30 is the most iconic.
