I haven't shot the 17hummer, but I own the 22lr and love it. The most accurate 22 I've seen. Honest 0.5 inch at 50 yrds.
With even mid priced 22lr loads, most Anschutz 64 or CZ rifles will do even better than that for five shots. Try some SK Standard Plus ammunition, and you might be pleasantly surprised. My base model CZ455 is averaging just under 3/8" with that ammunition. My Anschutz 54s are averaging around 1/4" with the same ammunition.
