All you can do is start at the beginning and work your way up. Your gun may deliver higher end velocities, it may also never get there. On a 24" barrel, for a 250gr anywhere over 2700 is in decent territory, 2750 is in the upper end. I never bothered with 225's. 210's can hit 2950 range at the upper end, anywhere around the 2900 mark is quite alright. You'll get people telling you about higher velocities than what I have said here, some push the limits, some have longer barrels, some guns are actually inherently faster. And there will be people saying they can't get what I've listed, that could just be because of the gun they happen to have, it won't do it.
When I picked mine up new in 1990, I bought Federal Premium 250 Noslers to blast off and sight it in, only got 2440 out of them. Same bullet got to 2750 in that gun. They were advertised on the box at 2660. I've been using RL19 on the 210's and H4831 on the 250's.