"Welcome aboard, and glad to see the information helped someone, without them soliciting for help - THAT is why the info is up there, and it's great to see your words.
By chance, where were you referred from, if you don't mind?"
Someone on Snipers Hide put a link in their post about troubleshooting a PSA 308AR. Been a member there since 2009. My PSA 308 was built from a parts kit, 16" bbl. I later changed the bbl to a Faxon pencil barrel to try and make it a little lighter. But I had many and various problems with the gun from the get-go, and changing the barrel did not effect any of them. The MAIN problem I had was random case head separations with starting-level loads. I finally got hold of some headspace gages and found that the gun would fully and easily close on a no-go gage. I had already changed the bbl so I decided it had to be the bolt. Bought a Lantac bolt assembly which fixed that part of the equation instantly. Your articles fixed the rest. I couldn't find an Armalite mid-length or "carbine length" gas tube but did find out another company makes the same tube-LBE Unlimited. Worked like a charm.
Again, thanks to all for the help and the welcome messages.