And to add to what I said above. If a raccoon is shot and wounded, it will run away. But it will remain alive for days suffering in some wooded undergrowth. Nobody wants to see an animal suffer and they also become more dangerous when wounded like any wild animal.
Just my two cents.
A .22 long rifle cartridge tip weighs 40 - 60 grains. I have Premier .22 cal pellets there only 14.3 grains. A raccoon is a very powerful wild animal. I would not recommend attempting to kill one with a high power air rifle. Even if you could buy 40 grain pellets for a high power air rifle...