That video I posted shows 16" HK416s exhibiting a pretty substantial amount of backpressure/gas out the ejection port...so much so that I didn't even think it was possible for a piston gun to do that.
Was your experience entirely with the 10" models, or did you see a big difference in suppression performance between the 10" and 16" models? Also, which suppressor did you guys run, the M42000, Surefire, NT4? Something else entirely?
As another point, PFPA is attempting to get HUXWRX Flow 556Ks for their 10" LWRC M6 piston guns, specifically because of the blowback with their current Surefires. I don't have any of the experience on piston guns you do, and whether the LWRC option counts as a "proven" host on the same level as the 416...but, just figured I'd mention it.
Thanks for any insight on the above questions.