There are several options here. I'm sure you will find that .270 - .30/06, class factory ammo, regardless of bullet weight, is pretty harsh on pelts. The first option I would suggest is to load cast bullets at 16-1800 fps. Long for caliber cast bullets often give better accuracy than shorter ones, and 190-220 grs is about right for a .30 caliber rifle. You can buy good quality cast bullets from MT Chambers. The problem here is that the trajectory will not be particularly flat. Jacketed bullets can be down loaded, and if you find one with a heavy jacket and load it to say 2000-2300, it might not expand much on a coyote sized animal, but will still be useful out to 200-250 yards. In .30 caliber, FMJ military bullets have been used successfully for fur, but some rifles shoot them well while others don't. A more accurate, though more expensive bullet is the Barnes Solids. They offer a 120 gr banded spitzer solid in .277" and a 165 gr banded spitzer solid in .308". As long as the coyote was hit broadside, the bullet would exit before it had time to swap ends.