A guy with a 300 can use a 223 to get a lot of trigger time. They have similar trajectories at the ranges I would shoot. The skills are transferrable.
Yea, I plan to largely hunt with my 6mm but do 95% of my training with 223.
Though this year I brought both my 6.5 and 223 to deer camp intending to hunt with it and ended up just hunting with the 223 since I was so comfortable with it. But either wouldve been fine.
