Barrel Extension Separation!

[Hansel&Grendel]

In this case, the barrel index pin was neither sheared nor came loose. It remained intact on the barrel extension throughout. Separation occurred regardless of the barrel index pin. I do recall that the vendor lost their chief machinist at about the time of my purchase and that those left behind had to quickly learn to the machines to keep up with demand. I also thought to re-visit a bookmark on my computer from a Shooting Illustrated article (12/2017) about nitride barrel finishes; excerpt:
"... the nitriding process tends to loosen up barrel extensions. So, existing AR-type barrels that are treated must have their extensions properly timed and torqued afterward."
https://www.shootingillustrated.com/arti...-finishes/