A while back, I neglected to drain the powder from my RCSB Powder Measure hopper after I was finished reloading. My fault. I left the Bullseye powder in the hopper for several weeks. The Bullseye powder reacted with the hopper material and the powder ended up building up and sticking to the walls of the hopper, permanently! NOT DUE TO STATIC cling.
RCBS saved my butt (this time) and is replacing the hopper.
I have the highest respect for this company and all of their products. If a company maintains the best reputation, it will not follow those that put profit ahead of quality.
If you "Google" any questions about RCBS products, it will bring up a video to show customers how to do things; such as remove and replace the hopper on a RCBS Powder Measure.