Accurate Powder Delivery

[Dino82520]

When loading for accuracy I use a Lyman Gen 6 powder measure and scale. I set it to deliver 1/10th of a gr less than my desired charge and then trickle to bring the charge to desired load. I have found this method pays off in smaller cases like .222, .223, .240 Wby and my .250 AI. Larger cases 30-06, 300 Wby etc. don't seem to be quite as critical. Does anyone know for sure what the ammo producers use as a quality control mean for accurate powder volumes?

[Grouchy]

I know someone that works for Federal. I'll ask. I use an electric scale as well. I have checked the electronic scale a number of times against a balance beam and found zero difference. 

[Dino82520]

I know someone that works for Federal. I'll ask. I use an electric scale as well. I have checked the electronic scale a number of times against a balance beam and found zero difference. 

I'm just curious as to the tolerance is, +- 1/10th of a grain, 1% volume?

[Grouchy]

Consistency is the key for next to zero difference between loads in a factoy setting.  It would be way lower than 1% in larger cases. The guy I know works in the office as an accountant,so I'd take this info with a grain of salt.