In NH, where I lived for 37 years, a 30/30 was the ideal deer gun. The vast majority of shots were less than 75 yds, and many under 50 yds, in pretty thick cover. Under these conditions you're better off with a 30/30.

In open land where you'll regularly shoot over 100 yds, the 243 is better, but the 30/30 is plenty good to 150.