I highly recommend the CZ 457 if you ever get the chance. All of mine group well, not as well as my Anschutz but extremely pleased, and you can switch barrels. My 17 HMR is the best at 100 yards easy .5 inch at 100. But I do have a Lilja barrel and Jard trigger in a aluminum chassis.I have a 22WM and a 17SWM rifes. The 17 doesn't group very good. I felt it would do a better job. /To many other items on my plate to mess with it. Just watching. The ruger I have in 22WM, didn't group very good either. It is a compress barrel. I took about an 1/8 out of the forearm and got it to group to about 1" @ 100yds. Not bad, but not great either. I had the trigger worked over too.
I have a Ruger 77 in 17 WSM, and it shoots well enough for hunting accuracy pretty much 1 inch to 1.5 inch at 100, and love carrying it as my truck rifle. It has the 24 inch barrel and just balances really well for me.
My Sako Quad with the HM2 barrel is really fun, and extremely accurate. That is probably my favorite rimfire cartridge.
Love my rimfires, and nothing gives me more pleasure than shooting rimfires, all of them.
Still windy where I live hopefully I will get out this week and test the 21 Sharp.