There is a small little hand held primer pocket swagger/cleaner that is great for cleaning the primer pockets. Even if you deprime before you tumble the brass, the primer pocket is so small the normal media can’t do an effective job of always getting the pockets clean. If you deprime after tumbling some of the material in the primer anvil will always remain and can be transferred to the primer seating button. Disclosure - I don’t own a Dillon but have seen this on an RCBS and a Hornady so I am assuming it can be a universal problem.
The little pocket swager is really more of a cleaner than a swager. It’s simply held between your thumb and index finger, inserted into the shallow primer pocket, and twisted 3-4 times. If your anal about the problem, you could tumble, deprime, and then take a bunch of cases and sit watching tv and clean the pockets before reloading. I’d rather do that than stop every 4 or 5 cases and check the seating punch and/or giving the primer seating components a spray with air.
The little pocket swager is really more of a cleaner than a swager. It’s simply held between your thumb and index finger, inserted into the shallow primer pocket, and twisted 3-4 times. If your anal about the problem, you could tumble, deprime, and then take a bunch of cases and sit watching tv and clean the pockets before reloading. I’d rather do that than stop every 4 or 5 cases and check the seating punch and/or giving the primer seating components a spray with air.