And my good buddy @11B CIB learned me exactly what was. Nice!
It's for taking up the slop between the lower and upper. I hadn't seent this before, but I still consider myself a n00b when it comes to everything AR.
This is an aero lower, so I decided to check my other aero lower. No hole, but I have a really good relationship with the machine shop down the road from where I work.
It's for taking up the slop between the lower and upper. I hadn't seent this before, but I still consider myself a n00b when it comes to everything AR.
This is an aero lower, so I decided to check my other aero lower. No hole, but I have a really good relationship with the machine shop down the road from where I work.