Quote Originally Posted by TheRifleman View Post
I figured it out, an out of spec extension. No more cheap purchases from no name parts. Once again I relearned that parts is not parts and that cheap is not that effective. I got it from Aim Surplus way back when and while it runs fine or so I had thought with a Microbest BCG, I did this time notice that with any BCG there was a sluggish return to battery. Hardly noticeable but we caught it in slow motion happening. Something on the Griffon's carrier design with that bulged ring on the surface of the rear of the carrier is having a more dramatic effect. When I put the same Griffon on a Geissele tube, FN tube, or a Colt tube, it works as designed. So after relearning why cheap is just a shortened name for tolerance stacking, I ordered an LMT tube for this LMT lower, and decided to try out that Vism alignment block for buffer tube installations.
Thanks for the follow-up. That makes sense that if the ID of the extension was a tad too tight it would constrict on the geometry of the Griffin carrier.