I have several rifles that have been built by the same smith on the same platform; Ruger 77, tang safety rifles. Whenever I build or purchase a rifle my son ends up with one too. What I have noticed is that some of the loads in his rifle do not like what my rifle likes. My son has a 35 Whelen that will blow primers out with the same load that is the most accurate load for my Whelen. I can say the same about several other rifles that are exactly the same. I would like to suggest that maybe purchasing a set of comparators and some dial verniers would help figure out your situation quickly. I bought a tap and a tap drill on Amazon and I make my own "special cases" that are used to make the measurements to determine where the bullet meets the lands.
