I leave the primers in... tried both, and spent more time removing media from flash holes... no benefit that I could see to de-capping first....
just my experience..... to each his/her own
the fear of leaving a piece of media (by chance) in a flash hole worries me!
every time you decap, you stick a little metal rod through the hole to push out the old primer, so I don't see how you could leave media in there. I've loaded, oh, 80k-90k rounds in the last 5 years, never happened yet.
-rvb
<snip> I dump all shells from a days shooting into one of my tumblers when I get home, then sort them into storage bins. That way they are ready to go next time I'm ready to reload them.