Been awhile since I looked into this stuff. My Beeman R1 spring air rifle in .20 cal is extremely accurate, powerful, and has an adjustable trigger, and doesn't require CO2 cartridges. I imagine nowadays they are worth a pretty penny. As I recall, they import/imported a wide range of top notch air rifles that will last a lifetime. Check 'em out. My favorite ones are the ones made in Germany (Weihrach??). I think they may be pricier but well worth it if you're thinking longterm food.

Once I had occasion to eliminate a trash bird in my back yard. I would estimate he was about 30 feet away up in a tree. I popped him with the R1, there was a puff of feathers, and I couldn't even find the beak. So, if you want to eat small birds, it's a bad choice. But for bigger prey, it should do the job pronto. Around here there are enough pigeons to sink a battleship on any given day. Squirrels too. And opossums. And seagulls (fishy taste?). I could probably shoot this gun every day for the rest of my life 'til I was sick of it and not spend more than $50 on ammo.