Brian, Thanks, I know we are not the only ones who have done this. Agree on the 380 as it is worse with the ball powders as they go everywhere. Stick powders are not that messy.
I have been reloading for over 40 years now. I only keep one powder on my bench at a time. I always empty any powder measure I use when I finish.
I always exercise caution and awareness when I reload however when I first started using the chargemaster, after I dumped the powder I was using in the original can, I left the valve open.
It was when I started to fill the chargemaster, I would forget to make sure the valve was closed. Th orange sticky was to remind me. I think I am finaly over it.