Re: OP. Writing specifically to your question, I have with complete satisfaction routinely used .22 LR ammunition in various and sundry rifles to take common small game animals. I have also used it to kill vermin up to approximately 40-50 pounds. Distances have been anywhere from hard off the muzzle on out to maybe 100 yds. Firing up close I've not had any problems with the .22 LR round being effective. Firing at longer distances, I've always been able to use a good solid prone position which allowed me to place the shot precisely for a one shot kill.
While I have carried various .22 LR pistols and revolvers, I have only used them on small game and a few birds, a task at which those handguns and the .22 LR round excelled.
I have not ever used a .22 LR firearm to kill medium or large game as it is illegal. I have seen my father and others use .22 LR firearms to kill hogs of various sizes when they were trapped/penned. Between 1979 and 1983 I worked as a security guard at various locations in New Orleans, LA, mostly a shipyard and a construction yard. I carried a little Ruger Mk. II in my pocket as that was what I could afford. It was loaded w/ .22 LR Stingers. I used it on rats, sea gulls and the dogs that were a everpresent problem. It was supremely effective. It never missed a beat. It never failed to fire. If a second shot was needed it was only because I failed to make a first round hit. Because it was inexpensive, I was able to shoot it so much that I became very proficient with it.
Now that deer season is over, I will be wandering the woods/fields mostly armed w/ my beloved 18-3 or a new to me Ruger Mk. II target competition model pistol, either of which will be loaded with CCI Mini-Mags as this is a round that shoots superlatively in both handguns. There will be opportunities to hunt a variety of small game. And there will be varmints in season. And, there will be other things that need shooting such as pine cones, dirt clods, etc.
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