Airgun manufacturers tend to "overstate" the capabilities of their products. Any pellet going that fast out of a springer/break barrelI has to be an extremely light pellet - you should be using a much heavier pellet for the "1 shot kills". I would guess the rifle you mentioned is a .177 with the speeds you are quoting. A .177 should never be used for coon size game...it just isn't enough rifle to take them humanely. Your working range for the smaller size game will all depend on how accurate you are with that rifle. The distance you can keep 10 out of 10 shots in a 1" square would be the distance that you probably should hunt at. I would avoid pointed pellets as they would probably just blow thru with very little knock down power. Try usiing kodiaks, eu jins, jsbs or pellets over 16gr for the best results.
sgS