To be absolutely SURE of what, MY Rifle and Load, is truly capable of, I will shoot at least, 3 or 4, 5 shot, groups, over a period of, Two "sessions".
Then, to re-test and check POI,..I'll periodically shoot, 3 shots after, that.
I start, a New Barrel on, Load development after, 40- 50 Rounds thu it, to check,.. Velocity and group sizes, as I START to, "Work up", loads.
But, I "Lap" / Polish and carefully "Break in", my Factory, Barrels, FIRST so I am getting, MAX Velocity, a little quicker than, most people, do.
I say that, my Tikka T-3, @ 7.7 pounds, in .270 WSM, used for, Elk, Moose & Lge Mule Deer, is about, a 1/2 MOA Rifle, as I can "usually" shoot groups from, 3/8th's to 1/2 MOA at 100 and 200 Yards and on, my BAD Days, it can jump up to, 5/8 th's to 3/4 MOA, group,.. LOL.
At 500 and 700 Yards, I'm Happy to shoot, a ONE MOA Group's.
I usually take 2 Rifles out, at a Time and rotate them, every 2 or 3 shots to, KEEP bbl's,.. Cool !