A .243 is an EXCELLANT rifle for hunting. Shot placement is important. The velocity of a .243 is very fast. This equals very low bullet drop at ranges up to 300 yds.
I've killef lots of deer with my ruger m-77 in .243.
I also have a 25-06 in Ruger #1 single shot
And a 30-06 in Ruger #1 Intl.
Remember the deer doesn't care what you shoot it with....carry what you're comfortable with.
I shot a bobcat at 150 yds last week with .243.. exactly where I put the crosshairs.
put the round through the neck you don't have to track them very far. Dead in tracks