What defines "best"?
I'm very fond of .17s. If I were being strictly practical, I'd keep my current .17 HMR and own nothing else smaller than a .25-'06. The distances here are generally short and most of the shooting is at rodents slightly smaller than a prairie dog. The number of shots fired at things the .17 HMR won't handle well are few enough that using a .25-'06 for them doesn't create any issues.
At the same time, I really like the .17 FB and .17 Remington, and my current .204 is great. The .204, especially, does do things the HMR won't, but there aren't that many such shots in a day, so much as I like it, it might not be the most practical choice. I'd have to say the same for the CF .22s.
If I lived somewhere else with a different mix of varmint sizes and / or different shooting distances, the answer would surely be different.
I think my next varmint rifle project will being life as a .223 and get rebarreled to .17 Remington.
Tom
