Since I used to reload for years I know exactly what you're saying and totally agree. I did have a Ruger 77 Stainless Synthetic in .300 win mag that would take ANYTHING (factory ammo) I gave it and put ALL of it in the same 1" circle. I'm talking different bullet weights (at 100 yards), different brands etc. It never changed zero. I have no explanation why but I spent many hours on the range with that rifle and put down every animal I ever shot at with it. I could not improve on it with my handloads and I tried ball powders, extruded powders, different brand and weight bullets.