I just now ran across this old thread. In my situation I lucked out on a stainless steel Ruger Single Six .22/. 22mag. 6.5in barrel. Fun to take hunting for small game.
My friend Bonnie & I competed with Marlin 917V 17HMR rifles at 200 yards for a long time. The rifles had $30 Tasco scopes on them and both of us shot High Master scores at 200 yards. The 17HMR got me the only perfect score 500/500 I ever shot and I got a 499/500 too. Bonnie always shot around 495/500 with her rifle at 200 yards. She also got a 499/500.
Our friend Adam wanted to try my rifle so he dropped to prone with my bipod and fired an "X" at 200 yards......his first shot ever! The rifles will shoot!
The poly point bullets will out perform the hollowpoints.
The down side is that a .17HMR barrel when new will copper foul. When accuracy degrades, you need a good set of cleaning equipment. Plan on spending $50 on cleaning goodies. Cleaned properly, accuracy will perk right up.
Academy Baytown had .17HMR ammo even during the worst of the last crunch.
The correct/best answer to your question is....buy both the .22 and the .17!