My self imposed rule is to never have 2 different kinds of powder on the bench at the same time. I was loading 223's and had about 3/4 lb of TAC on the bench and about 1/4 lb can of BL-c2 on a table adjoining. I picked it up and poured it into the powder measure and set it on the bench. Dropped 10 rounds of BL-c2 in some cases and seated the Sierras. About this time my grandson came in and started pestering me to use the computer and I told him to wait a min till I got everything put away. Then I took the powder measure and promptly dumped the BL-c2 into the TAC can! The minute I did it I knew I had boo booed. Oh well, it made the trip to Mama Murf's rose garden. I know I am not the only one to do this but the only other time this happened powder was $3.05 a lb.