There's a real difference between a .177 and .22! Also, my gun is pretty hot so I'm not losing as much energy in the bird. When you hit them, you have to be taking a lot of innerds out.
I have to say, I don't lose all that many, if I aim well. Those who fly or run, don't usually go far, but in an urban neighborhood, 26 feet can get you two yards away. I'd say that out of the last 80 birds that I've taken, I've lost maybe 6 and I'd say that almost all of them didn't go far (I see them fall).
BTW, I had some luck. The late day feeding frenzy brought them in three more times for me so I got a total of 4 on the day. Add to that 1 more that I got a few minutes ago (A side, shot, btw. He flipped over kicked a few times, mouthed a curse at me, and then lay still).
On that front, I JUST got back from examining that last one and this time I took a very good look/feel. I have rubber gloves. I found the exit hole just behind the wing/shoulder. I could stick my thumb into it. Yikes. That's using a .177 crow mag that I'm worried about passthrough with. That's a powerful pellet/gun combo, I think. I can't imagine what the crow mags would do in .22.