[I see a post went up while I was typing - and that we said much the same thing!

]
Unfortunately, .22 handguns are some of the most individualistic firearms when it comes to ammo preferences. A 617 that came off the line the day before yours might have completely different preferences than yours does. So what works for folks here might well not work for you.
Based on shooting dozens of .22 handguns for over a quarter century, I would advise that you purchase a selection of .22 ammo and try it out to see what your gun prefers. Fortunately, .22 LR is relatively inexpensive and it's just
fun to try different ammos out. I just did this with a new .22 handgun yesterday (I keep a two or three dozen varieties on hand, and am often surprised with what turns out to be the most accurate from a given gun).
For what it's worth (which may well be nothing, as I've noted), my friend who purchased a 617 for the sort of shooting you describe (as well as some friendly competitive shooting with her local club) has gravitated toward the Federal Auto Match 40-grain RNL bulk ammo that's available from Wal-Mart in packs of 325 for about $14. It works well for her in her 617, and I've found it to be a nice, clean, accurate and reliable ammo in most of my .22 handguns. Nothing wrong with Eley match, either, which she's used in competitions.
(Interestingly, while this Auto Match ammo was accurate and gave decent velocities in the new handgun I was breaking in yesterday, it would not reliably operate the slide. My
friend's gun of the same model gobbled it up. Go figure: all .22 handguns are individuals.)
Good luck to you, and have fun figuring out what your gun likes.
