One thing about buying a Rifle You need to think about what Game Your using it for and do You plan on carrying it a long ways or will You shoot off a bench or use a Bi-pod or some type of shooting stick?If You go with a Bull Barrel it will probably shoot tighter groups but can the Hunter pack a 8lb Gun plus the weight of the rings,scope and sling on the Rifle and shoot it from a standing position if need be?
So be sure to check the weight of what Rifle Your looking to buy and what size Varmints/Predators You plan on shooting?
There is a Rim-Fire .17 HMR and if I'm correct a Center-Fire .17 HMR,I'm thinking the Center-Fire .17 will carry further and have more knock-down power....and ammo will cost more.
Don't leave out the CZ-USA Rifles,Model 527 American or the heavy barrel "Varmint" they are very well made and accurate.