500grains

I am a little confused! You are not telling us or at least leading us to assume that YOUR EYESIGHT AND MARKSMANSHIP are not of PAR EXCELLENCE?

Congradualatins on your new rifle.

From my limited knowledge of regulating DR's, I would find it very doubtfull that the same load for one rifle would be the load of chice for another. Do you know what the rifle was regulated for when it was built?