I ran some Herters steel case .223 Rem. Once. That $hit was so weak it wouldn't even cycle a perfectly functional rifle. I think I saw it cheap, grabbed a hundred rounds (in 20-rd boxes). When the rifle wouldn't get through a single box, I gave the rest of it away.
If it was Herters you guys were shooting, I wouldn't doubt the results.
I still suspect the gas port size - that's some tricky $hit on a real Dissipator, man. It's gotta be spot-on to run those guns all the time. I honestly think it's to small. Drill up in one-step increments (what a PITA with a pinned gas block). You gotta drill, get out and shoot and test, fail possibly, go home, drill again once more, get out and shoo.... Aaaah, you get it.
I do have a range I found closer to my house. Road trip with suspected firearm, tools go to the range, work performed on-site...
I'm just sayin'... <dontknow>