In my mind, I KNOW I WANT my primers removed before ultrasonic or wet tumbling (without pins) to promote improved pocket cleaning. But… for a couple years now, I have off and on NOT deprimed before cleaning, and I’m not terribly convinced it actually cleans the pockets any better or worse whether I deprime or not.
As a chemical engineer myself, I think there may be some creative chemistry going on - a hint of pseudoscience - to convince me that ultrasonic cleaning with primers in place would chemically or mechanically weaken brass. I’d certainly expect that yes, steel anvils WILL effectively be plated when they come out of the bath, but I’m not terribly convinced that mass of leached nickel from the brass would be influential, even after multiple firings, and certainly not substantially moreso than the dissolution which would have happened without the presence of that steel. I also would expect that physical galling from the micro-collisions between the primer cup and pocket would be so ridiculously inconsequential as to say it simply isn’t…
The opportunity for trapped moisture is far greater influence in this discussion than any detriment to the brass.
