Problem cleaning out my RCBS Chargemaster

[7222 Hawker]

So I got dump out the powder resevoir in my Chargemaster. I has been full of Bullseye for a couple of months as I have been loading .45 ACP. When I dumped it out, there is a crust of powder covering the inside that is very difficult to try and scrape out. Is there something I can run through it to break down the powder and is this a problem with Bullseye? Never had this happen with any other powder.

[Full Clip]

Did it get some moisture in there?
What about using polishing media? Just fill up and run through.

[calidude]

I discovered that I can remove my transparent plastic powder reservoir... Life is so much better afterwards

[Fjold]

I empty mine after every use. I was told that exposure to light causes gunpowder to break down but I can't prove that.

[anyracoon]

Several years back, probally like 15 years ago I left some powder in my RCBS powder measure for a week or so. Powder actually etched the plastic on the inside of the tube big time! Last time I did that.