I don't think the coyote will notice the difference.
First coyote I ever shot was with a M70 in .270. Sure it will work. Good practice shooting the rifle at real targets too. As a general rule, a coyote will get your blood pumping as much as any deer so learning to control buck fever can be a big benefit. If he wants to take up coyote hunting on a regular basis he'll probably want to opt for a .22 caliber centerfire but for now that .270 will do just fine.
You do realize that once the coyote bug bites you, you'll end up with 4-5 "coyote guns". I've got a Savage 24F for in close work, a .22 Hornet for more residential areas, a .22-250 for... can't remember why I bought that one but it shoots great, a .243 for serious coyote work at longer ranges, a .223 that stays in the truck for incidental coyotes and that 30 minute stop on the way home from work, a .17 Mach IV because, of couse, the other guns don't fill that particular niche.... I think you get the picture :wink-yellow:
I just tell my wife that it's like her shoes - you need black pumps, black heels, black flats, navy pumps...
I use a 270 on em,but then i dont save them for anything,just thin them out and it gives me a chance to shoot a gun that i like.If he reloads he can go get some 100 or 110 grain bullets,doubt you would find these on the shelf as its hard enough to find 130 gr's on the shelf
Now if i was saving the hide it would be a different story,id probably go get a new .223 or .243.
Well I'm back from the trip now. My buddy didn't get a thing. It was his first time and he was more fascinated with the fact that I called a coyote in, so as soon as it came in he made too much noise and the coyote split. On the next stand I got a nice silver at about 30 yards. I'll post the pictures as soon as they develop.