RE: Powder Measuring Accuracy?
I agree with bigcountry. I use an RCBS 505 scale for all my rifle loads. I set the powder thrower just shy of the intended charge and use a trickler to bring each charge up to the correct weight. I have an old Pacific powder thrower. and probably like most, extruded powders are the 'toughest' to throw accurately. When I am loading for my handguns using flake or ball powder the thrower is very accurate. I usually weigh every 10th charge to be sure the thrower hasn't changed its charge weight.
Its amazing when you read some reloading manuals that state that the powder charge is the least important characteristic to accuracy. Yet you have a lot of experienced reloaders, including myself, that weigh each charge and note a noticable difference in load accuracy with a variation in charge by aslittle as 1/2 a grain of powder. And yo also have guys just charging their cases directly from their powder thrower or using the 'dipping' method like the Lee dippers to charge their cases. Thsi could be very dangerous especially when using max or close to max charges.