.243Love ve it or hate it
First off, happy new year to all and sundry! Glad to be a new member here!
Secondly, Gunnut69 and Kyode said what I was going to, otherwise this would be a lengthy post about getting a gun fit for the youngster, etc. etc. My son & I shopped and studied for 2 years before he was the minimum legal deer-hunting age, and ended up with a .243, Winchester Youth Model. We also took a Hunter Safety Class, together (although I didn't have to), viewed umpty-nine videos on stalking, deer anatomy, butchering, etc, etc. AND we put in our range time together. The year before he was legal he voluntarily came out with me on opening morning and sat motionless with me on my stand, holding no gun, for 2 hours in 0-degree weather before admitting defeat. When he got his license the next year, we both knew he was ready. And we'd had a ton of quality time together.
My boy would not have been as confident with anything with more recoil than the .243. He was then rather small and slender. The Winchester YM fit him perfectly, and he was able to put holes where he wanted 'em with it.
I agree the .243 is a marginal deer gun. My boy knew it too, and he knew where he had to put a bullet. I loaded 100 gr Nosler Partitions, and the deer he used 'em on never knew what hit 'em.
2 yrs later I had to replace the stock with a full-sized one. Son was still slender, and he still needed the light recoil. The new stock necessitated more quality range time, oh darn.
Since, son has gone off to college, and has filled out considerably. He could now handle a full-house .30-'06, or heck, any of the huge magnums, but I haven't had him home for deer season for years. When or if I ever get him back here for deer season, I'll suggest a bigger caliber, but I think I know what his choice will bethe rifle he learned on, and felt confident with. And I am certain that he'll still have the understanding to use it properly.