The rifle I developed my load for
is a 1943 Remington 1903A3 with a GI 2-groove barrel. I did glass-bed it, scope it, and add a Timney trigger. And I neck-turn my brass after sorting cases by weight, and ream flash holes and true up primer pockets.
With a fixed 4-power scope I can get 1/2 MOA from this rifle using 50 gr 4064, CCI large rifle primer, and Hornady 150 gr spire point bullet. Groups grew a little over the last few years, but then I had my younger brother shoot it and they shrank again, so it's me.
I used to weigh bullets..waste of time.
Weighing charges: bench-rest shooters don't. They use a good measure and throw charges for their tiny groups. I suspect it's not so much consistent weight, which after all could vary with atmospheric conditions, but consistent VOLUME, which an accurate measure will give you with proper technique. And that's why weighing cases is a bench-rest practice; consistent thrown volume in consistent-capacity cases.