RE: 243 and deer
I'lltypically use a .30-06 if hunting alone. If I'm hunting with my son, I'll use my Rem 700 .243. He shoots a NEF .243 single shot and we use the same ammo. 100grain Remington Core lockt!
The .243 is a great deer rifle. I wouldn't hesitate to take a 200 yard shot at deer.