I would agree with Davecole.
On a calm day, a .22 (at 28-32 FPE) can be effective to about 65-75 yards. Once the wind blows you need more power and a heavier pellet. Last time out I hit 2 P-dogs at 100 yards with my .25 Marauder. I had to allow four mil dots for the wind. I missed quite a few shots just due to playing the wind. If I had a .22 I would have had to allow even more for the wind and I would have just given up. With a P-rod in the wind, your limit would be about 35-40 due to the lower FPE. If you attempt to hunt P-dogs with a P-rod, I would recommend you do it on a calm day. I have two rifles that are at 14 FPE and I routinely target shoot to 50 yards (never hunted with them). I can get some pretty nice groups when the wind is mild. Once the wind picks up, I choose a more powerful rifle.