I am looking at purchasing a BCM mid length upper with 12" DD lite rail installed by BCM. I believe BCM uses a MI lo pro gas block attached with set screws to the barrel. Everything else I have has a pinned gas block. Is there any concern about using a set screw attached GB for every day/patrol type use? Anyone have problems with the GB working loose? I know first hand that BCM makes great stuff and figured that if they do it, it must work… but I wanted to ask.