Buy a .22Mag Rifle, semi-auto Ruger 10/22 would be my choice. Then get a spare barrel from here riflebarrels.com in .17 HMR and you have two rifles.

Another site is outdoorguides.com .

It might be cheaper to start out with a 10/22 in .17 HMR then buy a 22 MAG barrel.

From what I have heard, the .17 is good for sage rats, sqirrels where legal, and crows, but they should not be used against coyotes.

I have had a Remington 597 in .22 mag for about 5 years, and am looking for a barrel in .17 HMR.