The 17hmr has an appeal over the 22mag in rifles only because of the accuracy the V-max bullet achieves compared to traditional 22mag rounds. However with the 22mag now offered in the v-max, I find the 17hmr not worth buying.
In a 17hmr handgun (even if it does come with a 17hmr cylinder which I forget if they did)
- The rounds are expensive
- The 22mag is still better on critters
- Even if you put a scope on it and want to shoot at 100 yards, the 22mag is now offered in a v-max washing out any advantage the 17hmr had.
To answer your question (finally)
I suspect the 17hmr from a pistol will act much like the 17hm2 does from a rifle. It's still a very devisting round on small game (think Stingers) and not enough on larger things like coons and opposums.