I had thought about the .17 HMR myself, and well later will send my Sportster off to H&R for the .17 HMR barrel. I found my little Sportster for a good price OTD $139.99 and took it out this last week, well I'm glad I made the right choice off the bat between the two calibers.
For now, pretty happy with the .22 WMR and the way it shoots, but now I got to try the new 30 gr V-Max or the Remington 33 gr AccuTip-V bullets. I do believe the Hornady 30 gr V Max is pushing at 2200 fps, which is much better.