Hey Dave,
All my air rifles are for hunting, that's what I purchased them for and that's what they are used for, the .22's as well as the .177's.
I will freely admit that I personally prefer .22 cal for small game hunting, but I use my .177 guns all the time and cleanly take small game up to rabbit and squirrel size. I follow follow 3 basic rules when I'm hunting,,,,, 1) I reduce the range to the target as much as possible and have a self imposed range limit of 30-40 depending on the conditions of the shot. 2) I only shoot if I have a clean, unobstructed shot and 3) I always strive for a head shot if it's possible.
Following these rules I hunt successfully with all my rifles, both calibers, and cleanly and humanely take game. I'm not going to tell you that I never lose a game animal after it's hit because I have,,,, but those instances are few and far between. I feel terrible when that happens, but I when it does I will spend whatever time it takes to try and locate the animal even if it means putting the rest of the hunt on hold and I also know that these instances will happen occasionally when hunting,,,, it's just part of the sport.
As for "pest control having different rules than meat hunting",,,,,, I disagree. This is just my personal opinion and of course only applies to me,,,, but I feel I have a moral and ethical obligation when hunting to insure that the animal I am hunting is killed as quickly as possible and as humanely as possible and that I must do everything I can to insure that takes place,, whether I'm hunting a filthy barn rat or a rabbit. Following this belief doesn't make pest hunting any harder or more difficult at all,,,,, I feel it just keeps me bound to a set of ethical rules to which I follow.
Anyway,,,, just my opinion for what it's worth. Enjoyed your post,,,,, good to think about these things from time to time,,, it's good for our "hunting soul" :)
Jeff