That would be a tenth of a grain and an average at that.
If you had a repeatable method of throwing charges, firing and chronographing, you would find out that a tenth of a grain difference in charge weight, depending on powder used, could lead to a 5-10 fps change in velocity in a 308 round for example. A 10 fps difference in velocity would result in a 3 inch difference in drop at 1000 yards. So even if everything else was perfect, the first two shots would be further apart than the 10 shot record.
http://bulletin.accurateshooter.com/...ory-be-amazed/
You, your gun, the deer you shot 60 yards away from your blind might not ever see the difference but that doesn't mean there is no difference.