I have some of the CVA or traditions plastic measuring containers and they measure different than the BH209 vials. I have no idea which is right. When planning my BH209, I would just weight them on my powder scale.
So far, I see at least every poster is aware of these discrepancies I've found.
Reading up on this it's not anything new, going back to posts in 2013 on other forums.
Some bottles weigh 70 grains per 100 grains volume, others 77 per 100. One poster supposed to have contacted Western and got a response to "rely on the volume measure method".
Another published outdoors writer sites, "there are no set standards as to measuring powder by volume". This is referring to the use of grains not CC, such as Lee and others.
Coincidentally I have two different manufacturers of 100gr powder measures that measure the same as to volume.