.243 is a great caliber, for kids, women and men. 100 gr hornady BTSP and nothing will survive that load through the chest.
while there are other good calibers, the .243 is the way to go. Its chambered in every manufacturer in any flavor you desire, ammo is at every store that sells ammo, it makes the top ten list for calibers sold in the US, for a good reason too.
Flat shooting, light recoiling, plenty power.
Put a a 100 gr and go deer hunting, put in a 55 gr and go yote hunting.
Handloaded it will push a 100 gr to 3100 fps and a 55 gr to over 4000fps
7-08 is another fine choice, but a deer wont know the difference.
I used a .243 for over 20 years, just recently went to a 7-08 just to see what all the hoopla was about concerning this caliber.
Not to mention I handload now, and a short cartridge that will push a 120 gr bullet to 3200 fps sounded awsome