1) It has to be subsonic to be worth a damn beyond 50 yards.
2) It has to be quality. Something that says "Match", "Target"...something along those lines.
Other than that, you're stuck with the same old "try lots of ammo" thing in your rimfire. They CAN be finicky. Not all chambers are, but enough are to be notable.
If you just want to be told what to do: Eley.
-Nate
I do have a .22 rifle that I love to shoot. It shoots good groups out to 50 yards, but 165 yards is a long way with a lot of drop.