The only real variable you are coping with, will be the interference over the locking bar and most likely an away from spec Lower with your BCG. That is what I am thinking. I have a batch of aero lowers coming in and acquired a PSA Easter sale on a https://frt-1574173.blogripley.com/36533780/the-smart-trick-of-rarebreed-triggers-that-nobody-is-discussing