Case Rim Expansion - 6.5 Saum

[gut_pile]

Primer pockets both measure .209 on fired and unfired brass

 

[Bob Wright]

I don't own any DBM's but I'm curious to know why the sheet metal body of the mag is that close to the rim diameter. .005 clearance is not what I would think is reliably functional. If it's the feed lips then that would be the problem to be solved. With the shell holder issue, there are others to try. Borrow a buddies?
Lastly, I would try sanding some of the rims to clean up any burrs from extractors etc. and retry those in the mag and shell holders.