Check out the link below SJAdventures. It will either clear it up or confuse you more.

As a general rule, just remember that the theory behind volumemetric powder measures is that they are based on real black powder (probably FF grade) so that volume and weight are equal. So a 100 grain volume measure of FF black powder should weigh pretty close to 100 grains.

http://www.huntingnet.com/forum/blac...han-yours.html