I ran into this problem when I started wet stainless cleaning my 45ACP cases. It got to the point where it took 2 hands for me to pull the upstroke. The problem is if the powder funnel has any imperfections brass will stick to them, and more brass will stick on that, and it snowballs until you have vertical lines of brass all the way around the powder funnel. I used my Dremel to sand the brass lines off, but that only made things worse because I created so many more imperfections. I called Dillon and they said this was normal for new or really clean brass, and that I should clean the powder funnel every 25-35 rounds. That is stupid and completely defeats the purpose of a progressive press, so I kept searching for a solution.
I removed the powder funnel and basically put it in a lathe. I started with 400 grit sandpaper to polish the funnel and went to 800, 1000, 1500, and finished with 2000 grit. My powder funnel is magically smooth now. It's also 0.003" slimmer in diameter which I believe reduces friction slightly. I have since run 2000 rounds of 45ACP through it, and it is still perfectly polished, with no resistance on the upstroke at all. I wish I had taken a picture of my funnel before I cleaned it the first time. The brass lines were so thick they created actual ridges you could feel. There was zero shine. This picture is after I polished with my Dremel and ran 100 rounds through it.