"you probably have a taper pinned Front sight base, which begs the question, why would you need to pull the gas block?"
A few years ago, after cycling through about 700 rounds, it all of a sudden became unreliable. It would only partially eject the spent case.
I cleaned it, lubed it, ensured the gas tube was clear, everything, and it didn't change the problems I was having.
A couple of people have mentioned that the gas block may not have been tightened down correctly and has slipped.
Is that the problem? No clue. But short of dropping it at a gunsmith to figure out, I figured I'd try making sure that the gas block is in the right place.
"you probably have a taper pinned Front sight base"
I have no clue what that means or how that would be applicable to the issue I'm having. Sorry.