Snipers working with the Lovat Scouts just after D-Day felt that if the rifle/ammo combination would "rim an English penny" at 100, it was good enough. I had this direct from the mouth of one of the men. They selected their ammo from available stores by lot number. If a particular lot shot better, it would be sequestered for their use and not just dumped into general issue.
Once the LOT had been settled, it was time for checking individual rounds for length, bullet runout, depth of primer seating, all those good things. They knew what they were doing and it paid off, same as in Match shooting.
BTW, that meant ALL of your shots on or under a 31mm coin (1-1/4 inches): toonie is 30mm.
Have fun!
.