apparently one can remove the sight stop pin without removing the sight on this lower. normally it is blocked from backing out, on this lower there is a notch. Probably a good thing if the pin is secure.
well it backed out and fell into the FCG blocking the trigger from resetting after a shot. this locked things up pretty good.
now where did I put that locktite
(pin shown set in place backwards, it normally pushes in with the fat part underneath)