I've shot a lot of Barnes X bullets over the years. Here's what I've found that makes load development go a bit quicker.
1. Start with a squeaky clean barrel. Barnes bullets don't work particularly well with copper fouling left behind from other bullets.
2. Try loading the bullets WELL OFF the rifling. Barnes says to start .050" but that's just a minimum. I've seen groups come together @ .100" - .150" off and even at a full .250" in Weatherby rifles.
3. Start with a powder that is in the middle of the burn rates that are available in the reloading data for the 25-06. Not the fastest or slowest, just somewhere in the middle. IME, I found it harder to get Barnes bullets to shoot best with the slowest burning powders but that could vary from gun to gun.
Good luck