You may wish to post this in the precision shooting forum. Far more tips from there.
I am a hunter, so I load for hunting. I had a buddy in Wilmot, NS that was into precision matches.
He weighed EVERY COMPONENT! He bought in batches of 10,000 (except cases, he only bought 1000 at a time). Weighed and sorted every case, primer, bullet. Checked the bullets for concentricity and sorted them again. Guy was NUTS! But he won stuff. It would take him a week to load test rounds and an entire day to load for a match. He bought huge kegs of powder from Ammomart that lasted a couple/three years and threw short loads which he then trickled up. He used a high end pharmacy beam scale for years.
He was constantly weighing, measuring, tweaking. Drove me crazy, but he loved it.
Dead now (15 years or so), I think his brother-in-law got all of his stuff and flogged it cheap.