You can get close but it will be a matter of luck to nut a longer-distance zero at 25yd. Between parallax error, horizontal offset mounting, and simply the resolution of impacts at 25yd, you're likely to be several inches off at 300yd, but in the ballpark. You can zero at 25 and be 'good enough' to set up paper and tune it in at 300yd. Putting a very EXACT optic height over bore into your calculator will help.