Originally Posted By shadowcop:
The locking lug stabalizes the bcg. Much less forward and aft movement which can lead to light strikes and feeding malfuntions.
BHOA operation, or lack of, is usually because the bolt catch spring is too much for the mag spring to overcome.
The now supplied reduced power bolt catch spring solves most of these issues.
And the BHOA is required to hold the locking lug tab in place. You will see a cut out in the center of the BHOA frame that the tab should fit in, keeping it from moving.
If the tab is hard to install from one side, try the other side.
Got it, thanks Dave.