ORIGINAL: caw_walley_eye
I've noticed when I pour in powder to the 100 grain mark it is different than after tapping the measure a couple times so I could potentially have two different powder charges here. Three if you consider when you compress a saboted bullet on top of it in the gun it is again compressed even more.
Generally a powder measure is considered full of powderwhen it has been 'poured' full of powder, not tapped/settled, thenpoured some more.
But it's really not important which way you do it...what is important is that whatever you do, you do it the same way every time so you have as much consistency as possible from one charge to the next.
FWIW, I don't bother spendingtime tapping a powder measure...I pour it until it begins to overflow slightly, then I gentlytip off theexcess,doing it the same way every time