Portland PD, in its infinite wisdom, refused to let Glock/Smyrna examine the G21s in question, even when Glock offered to fly Portland PD's so-called in-house "expert(s)" to Glock/Smyrna to witness the examination.
Bad ammo, plain and simple, confirmed by White Labs.
This is the same Portland PD that opted out of the Terrorism Taskforce.
I've fired tens of thousands of rounds of my reloads through G21s. If there were a systemic design problem, I'd have found it by now.