Dave I shot a big female coyote in between the shoulder blades using a 168 gr Barnes TSX open tipped .308. Distance was a hair under 200 yds and it was a clean entry and exit approximately the size of a dime for both holes. Her spinal column was crushed as the angle I shot from was roughly 25 degrees above the coyote (from a bluff top to a low swale). If all I had to shoot coyotes with was a .308, I wouldn't feel badly about using Barnes or even Amax tips, I have no experience with Scenars on game animals but I'm pretty sure they would hold together even on the toughest coyote shoulder without cratering.
I would not use FMJs to hunt with, for the amount of shooting that goes with coyote hunting I'd go with a slightly more expensive but expanding tip.