The old 173 FMJBT's, their weight difference was plus or minus 2 grains.
There was an article in the NRA Competitive Shooting magazine about the USMC rifle team and their reloading.
Their Ammo Techs loaded 600 and 1000 yard ammunition. Those guys weighed their Sierra match kings and discarded any that exceeded 0.1 grain.
There was a picture of a Marine next to a scale and a couple of boxes. One for the good bullets, the other for the discard.
( I would have killed for a bucket of their discards!)
Weight makes a difference but I am of the opinion that center of gravity is more important. And we can't measure that with a scale. If the center of gravity is off center the bullet will wobble.
Look, if your bullets only vary by 0.5 grain, be happy. They are great. Load them and shoot them and concentrate on your sight alignment and trigger pull. Errors in aiming are measured in yards, sometimes continents. I have a few that might have made orbit.