I do not have a .17 but wanted to get more thoughts flying so here goes.

Many have stated their opposition to using a .22 Hornet with 30-35gr bullets on coyote sized game and I would tend to agree. However, many folks do use the .17 on coyote with a 25gr bullet. I cannot speak from experience but it would seem that a .17gr bullet at 4000fps and a 35gr bullet at 3200 fps would be somewhat comparable. Am I way off on this?

Firstly in my opinion the 35 grain V-Max has roughly the same ballistic coefecient as a ping pong ball. With my Hornets I use the 40 grain V-Max and while it's length predicates it being used as a single shot it carries out much better, I've shot the two bullets side by side and after the 35 runs out of steam the 40 is leathaly accurate for another 100 yards. With that in mind and having shot boo-coo rock chucks and a number of badgers with it I would argue it is effective on coyotes(although I've never shot one with it) with certain limitations, maybe 150 yards. Experience tells me badgers are as tuff as coyotes and it flips the switch on a badger big time. Next on to the .17, I have a .17 Mach IV and shoot a 20 grain bullet about 4,150ish my self imposed limit on a coyote with it would be about 250 and I wouldn't shoot a running dog for fear of a bad hit. Better than either of these in my opinion is the new .204 Ruger looming on the horizion, I have a Tactical .20 and it's a coyotes worst nightmare 33grain bullet at 4,250ish 2 inchs high at 100 is 1/2 inch high at 300 about an inch low at 350. It's a coyote whacking laser, but so are any of the big .17's. Everone has an opinion, that's mine.---Shoot Safe---montdoug,

.22 HORNET: I have 3 17 caliber Varminters (0ne is a custom 17 MachIV and the other 2 are factory Remington 700's in caliber 17 Remington) and they do kill Coyotes readily. For instance last winter I had my 17 MachIV along on a calling Safari to far eastern Montana. We called in a Coyote that hung up at 320 yards (Leica laser ranged) and I killed it with the tiny little 25 gr. pill from the MachIV. I would not have even thought of trying my 22 Hornet at that distance. The MachIV was shooting the wonderful Berger MEF (maximum expansion factor) bullets and shoots pretty fast and flat out to that distance. The Hornet bullets I use in my Hornet and the speeds I get with my Ruger #1-B I just would not have tried that far a shot with the Hornet. But at 150 yards with my Hornet and its 35 gr. V-Max bullets I would not hesitate at all on brer'Coyote!
Part of the 17 vs. 22 Hornet question you pose must be answered with kind of an ambiguous or based on faith (and experience) reply. The higher velocity 17's kill way beyond what their 20, 25 or 30 grain bullets seem capable of doing. Remember that killing power (lethality) is not determined alone by foot pounds of energy! Other factors like explosiveness of projectile, feet per second and the ability of a projectile to make it into the vitals of a Varmint and then expend all its remaining energy there are VERY important factors in lethality (killing power). Lots of people around here use the 17's exclusively on Coyotes and Fox for pelt saving purposes. There is often a need for shots out to 300 yards in my neck of the woods and the 17's like I say remain popular here.
Last winter my good friend Brad killed a huge male Mt. Lion (within sight of my house!) with one shot to its lungs using the 22 Hornet and factory ammo. It was not an instant kill but was a relatively quick kill! That Mt. Lion is full size mounted on his wall and no pelt damage on it. Range was 25 yards as I recall.
Using each caliber within its limits will make one a happy Varminter!
Good luck in your endeavors.
Hold into the wind
VarmintGuy

You could always rebarrel and chamber for the .17 K-Hornet and cover both bases.