Just my ten cents...the 17 Hornet will certainly kill 'em with perfect shot placement. But day in and day out yer just gonna lose more coyotes with a .172 caliber than you will with a .224. We all know the coyotes don't stand there for you to get that perfect shot placement. I started out callin' gray foxes as young teenager in VA. We (my uncle and I) hunted almost exclusively at night. We used all sorts of weapons trying to up our kill ration and decrease fur damage. 22 magnum rimfires allowed perfectly lung-shot foxes to run off into the dark too often. So we go to the 22 Hornet; then, perfectly lung-shot gray foxes were dead right there, but sustained unsatisfactory fur damage. Everyone knows if you shoot any varmint in the brisket while he's looking at you straight on, he'll drop like a wet rag, almost regardless of the caliber weapon. That's not what I'm talking about here. I'm just talking about upping the percentages of kills and and harvesting good fur. We finally settled on the 12 gauge using modified choke w/3" mag, #4 buck or copper plated BBs (#2ish). This was the perfect weapon for us on the gray fox night hunts in VA. For one thing, we no longer missed. The foxes died quickly with only tiny little holes in their pelts. Now fast forward 10-12 years as we experienced a significant decline in gray fox density with the increase in coyote density, the same as the entire eastern side of the country.
I'm a huge .17 cal fan and own two 17 Rems that I reload for; a Model Seven and a 700 Classic. I've taken several trips west to call call coyotes...and get some reasonable action. It's not that fun to hunt coyotes in VA & NC these days without night vision, thermal, etc. It hard hunting and a guys is lucky to kill 15 coyotes/winter without $5K worth of night gear. Anyways, I've shot several coyotes with my 17 Rems and about half didn't go right down. I've recovered all of them but I've also had to use follow up shots on several. My go to gun anymore is my .222 Rem in the east, and my 220 swift when I go coyote hunting in the west. 40 grain Sierra HPs in the 222, and 52 Amax in the swift has worked out. Each provide minimal to zero exit wounds and no runners to speak of. I'm not a high numbers guy like Borkon or some of the other guys out west so they have the best data and experience. But it just seems sensible to use a caliber you can be more sure of (.224 caliber), that hits harder and introduces the additional shock needed to down a coyote sized animal. For the bobcats, it seems like a larger case centerfire 17's with higher energy would be a better choice than a hornet based round.
Again, don't get me wrong, I love these neat little cartridges and I tinker with them continuously. But when it comes to KILLIN, they haven't shown me they are right for coyotes on a daily basis, and in most cases, cats either. Not trying to spar with anyone on opinions just sharing some experience. Albeit, I"ll be back in GA in a week and I will very likely make a few stands calling coyotes with my .17 Rem. Heck like everyone, I wanna hunt with ALL my guns.
JB in NC