30 Carbine is kind of like an expensive 22 mag. The M1 Carbines are fun to shoot, but generally not in the same accuracy class as most 22 mags. 30 Carbine is great fpr rabbit to coyotes, but not quite enough for deer. Given the choice between the two, I would opt for the 22 Mag.
Never try to educate someone who resists knowledge at all costs.
But what do I know?