I bought a used RCBS Uniflow powder measure some time ago, and only recently took a close look at it. It looks like someone left gunpowder in the hopper for an extended length of time, and it reacted chemically with the plastic, fusing some of the gunpowder into the plastic, and giving it a fairly rough texture, almost like stippling. I'm a bit concerned that any powder I put in there will tend to hang up on the stippling. So, I figured out how to get the hopper off, and I went after it with some 220 sand paper, which definitely smoothed it down, but you can still feel bumps in the plastic. While I'm sure I can eventually smooth them all down if I mount it on my lathe and just go to town, is it worth the time, or just easier to get a new hopper (which seems harder to find than I expected).

My Hornady hopper is a little worse for the wear after a few years of use, too.

I wouldn't worry about it. You shouldn't leave powder in it for extended periods, and when you empty it just make sure it comes out. Probably as easy as just shaking it.

I have one that did this also, I am considering making a new one out of a better plastic. Dillons do not do this. If I could figure out what they use maybe I could order some and turn a few out. And make them clear. Hate the green.

If you contact RCBS, they will have the hopper and most likely replace it free of charge.

I had a similar situation with my 30 year old RCBS unit. Called them to order a replacment - they sent one free- no questions..

If you've sanded down the big bumps I wouldn't worry about what might happen, just what is happening. Fill it with powder and start running it through, back into the bottle. If it flows fine just go back to loading. By running through a bottle of powder you'll coat the surface you sanded with the residual graphite powder leaves behind.

I have a real ugly powder reservoir on one of my powder dispensers for my progressive. Doesn't bother the operation at all. FWIW, the only powder flow that matters occurs in the funnel portion below the plastic reservoir and you should always keep powder well above that level for uniform dispensing.

The thing about Uniflow powder measures (as well as Hornady, Redding, and Lyman) is that they dispensing parts are made of metal and when you operate them with a "firm hand" the powder flows more evenly and also shakes powder down from the walls of the reservoir.

Thanks for all the replies guys, I just now wrote RCBS on their Customer Service page, didn't ask for a new one, just explained the problem and how do I go about ordering a replacement. I'll let you know what happens.

I'll tell you my experience with Hornady, which may or may not be representative of anything at all, including RCBS.

I've called Hornady in the past with various reloading equipment problems, and they've always been very quick to send me free replacement parts.

The one time I emailed them with an issue, they wrote back explaining the process to buy a replacement.

They just emailed me back, asked a couple of questions to make sure they knew which one I was talking about, after I responded, they sent another email saying that one had been ordered for me at no charge.

I really appreciate this kind of customer service. It encourages me to give my business that way.
It's not with the expectation of "free stuff", but rather to know that in the unlikely event of needed help, they are there for the community.
Thanks for the update sir!