Looking for a good coyote and bobcat load for a 10inch 7tcu. Would the Sierra 100gr hp Varminter make a mess of things?

Do you want to save the pelts? If so, that bullet is not a good choice. If you want to save the pelts, your best bet is something like the Sierra 120 grain spitzer. You can drive it to 2000 fps using H335 and get a reasonably flat trajectory for shooting out to 200 yards. It will exit on every shot, but the exit will not be gaping as it will expand only minimally but will do sufficient damage to put the animal down in a humane fashion.

I had good accuracy from Remington bulk pack 130 grainers from Mid-South, over H335. I don't know the actual velocity, but based on the tables, I'd say it was under 1800 fps, which I don't think is sufficient to make the bullet expand in a coyote or fox. Winchester 748 worked well also.