Wood stock - semi auto - .223? Sounds like a mini 14 to me.
And a .243 would work. One of my first few deer guns was also my coyote gun, a Sako .243 shooting FMJ handloads.
Then a long time favorite is a single shot, a Ruger #1, 220 Swift... just to point out that you don't need many rounds, much less a semi auto. It's very rare that you get more than one (useful) shot. (Yes, the DVD Santa put in my stocking, ‘The Truth, Calling All Coyotes,’ was three inspiring hours of coyote herds racing toward the callers. I guess I should get some Primos calls because my calls seem to be 'One & Done' models.
)
Now I have a couple of ARs, one of them is a 24" bull "coyote rig." Other people have their reasons for wanting a semi auto - shooting doubles, running shots, immediate follow-up, and I figured their reasons were good enough for me (since I wanted to play with some ARs and couldn't come up with original excuses.)
And then I have a Rem 700 in .223... "For coyotes."
My point is, I'd tell your friend to keep economy in mind, holding back enough money to buy an XL safe for all the coyote guns that will follow.