I just got through reloading another 250 rounds of .45ACP and was checking my COAL and was getting a reading of 1.257-1.262. I have my seating die set @1.255. So after I got through loading a hundred rounds, I dug out my cleaner and cleaned it thoroughly and then re-set the die. I noticed when I ran my cleaner spray into the die, I saw some "gunk" come out. Here in Az we have dust build up everywhere. I asked my wife what's on TV and she said dust. Normally I load about 1K or rounds before I clean them but I think since our summer is over (Thank God!) I am going to clean them about every 500 rounds. I check about every 5-8 rounds when seating and then I usually case gauge all of my rounds. What is your policy? Tommy BTW- I was using my single stage loader and not my progressive.