like the others said the .308 with work fine for yotes as long as you don't want to save the pelt. If you reload, get some 110 grain m1 carbine bullets and load them up on the .308 brass. This makes for a smok'n load that decemates yotes and other smaller critters.
For the question about the G.I Bill. I used mine and it paid for what the loans didn't cover. Make sure to apply for the pell grants as well. It really helped out. My GI bill lasted through my Bachelors (already had an associates before using the GI Bill) and I am still using it as I start my MBA. I only wish I had opted for the extra 600 bucks investement for the "kicker" that they offered right before I got out. That would have made a huge difference.
Happy shooting and one piece of advice. Take some of the old books from classes you hated out to the range. After I wasted about 100rds of .223 on a statistics book, I felt great! (love math, and always got A's, but that darn stats class struggled to get a B)...
Lifetime member VFW and NRA
"Quando Omni Flunkus Moritati" (when all else fails play dead) -Red Green