Note to self re: sparrows.

Do not shoot sparrows with 40fpe .25.

I have birds that land on my pool waterfall and bathe, I'm mainly concerned with the rock and eurasian collared pigeons, which are fair game here, but got a sparrow (also fair game) and it made a mess. The corpse, 1 minute after shooting, looked like someone had stepped on it and smooshed it with their feet and there were feathers all over the place.

Now considering a .177... At the close range they are, my .25 might be too much even for the big fat pigeons, and the .22 too much for sparrows.
 
I've killed deer with a 338 Win mag (over kill), 222 Rem. (drop them where they where standing) and anything in between.I like my custom 6.5x284 but have a lot of 30 cal, 7mm and other 6.5 cal. powder burner. Went to hunting with handguns because rifles got to be to easy even on long shots. 
It is all about what you like to shoot and have the most confidence in. Shot placement to me is the most important thing in hunting. Yes the .177 will take out small game with a humane kill with a well place shot but a .25 or.30 cal will do a better job if you make a mistake and you will if you are human.
 
"jvrobert"Found a Crosman 1720t for about $100 less than usual from Academy, jumped on it. Putting stock on it.

Will get it up to about 12fpe and practice eye shots, should be fun with such a small, light rifle.
If my P-Rod is any indication, it will be a lot of fun. And just enough power for what you want to do. 12 FPE from a .177 is more than enough for body shots on sparrows and doves, and enough for head shots on nutters and also chest shots, if you don't hit the arm or shoulder first. 

You don't need eye shots not to make a mess of a sparrow, esp. with domed pellets. Just pick up the body by a wing feather to keep your hands clean and throw it somewhere the night critters will find it. I have a nice neighborhood fox that cleans up all my pesting kills for me. :)