From 0-as far as you can hit, a high power .25 cal. will kill from elk or moose on down. It is easier to place shots with less recoil. For varmints the sky is the limit. They are faster and flatter than anything larger, offer ample power and are superbly accurate. They pound the .244-6mm class and don't lose valuable traits to the larger cals. too bad. I realize this will start a huge **** storm from .260, .270, .280.,.300 fans but it is true. Bring it on if you have real experience. By that I mean enough to change my mind. Not likely!. I'd much rather hear from the .25 cal. fans on what they have observed. All opinions welcome. For what it is worth, the nearest competitor, the .270 WSM. has already come up well short along with the .264 Win. Mag.