I weigh BH209 simply because it is convenient, creates less waste and it is safe in the RCBS Chargemaster 1500 combo. I put tubes in a shotshell tray and simply move the powder funnel from one to the next until i have the desired number of loads.
I have not checked different lots for volume comparisons and ive always used Westerns conversion rate. I believe actual weight is far more accurate in achieving identical volumetric equivalent loads even though BH209 meters very well by volume also.