I shot the first head of game in my life with a 243 today. Not first animal just first with this caliber.
A Blacktail Spike maybe a 100 lbs on the hoof.
Laying in his bed looking at me,about 200 yards, federal cheap stuff, 80 grain soft point.
All I could see was head and neck. Shot him just under the chin, flipped him completely over backwards.
Yup Id say the 243 works good.
Carl