Congrats on getting your grandson a sweet rifle!
He has to take his hunter education class this summer so the ammo panic should be over by then.
The ammo panic hasn't really affected hunting rounds. It's mostly affected handgun rounds and semi auto rifle rounds, like .223 and .308, and surprisingly, 22lr.
If you can find someone that hand loads (or would like to pay me to do some 243 for you
) I would give the Barnes TTSX a try. You may be able to find these boxed in factory form already, but people have tons of success with these bullets, even if they are light-for-caliber. This one on MidwayUSA is listed at 80 grains for a 243, which is light, but the bullet is all-copper and has controlled expansion. Every review on the page is 5 star and says it had complete pass-through, which is more rare for 243. http://www.midwayusa.com/product/594032/barnes-tipped-triple-shock-x-bullets-243-caliber-6mm-243-diameter-80-grain-spitzer-boat-tail-lead-free-box-of-50
I load these exact bullets in .260 Remington in 110gr configuration and am going test them soon. What did the deal for me was when my dad could not get a bullet to shoot well out of his 300 mag. That was, until he worked a load with this bullet. His best group was .36MOA. He took this load to Montana for a big game hunt and took 2 bulls, along with 1 big mule deer. It delivered the kind of performance he was looking for, since all the shots were around 300 yards.