Quote Originally Posted by 3 AE View Post
I'm a bit confused. Isn't the A2 upper receiver the one with a built in carry handle that has a rear sight that has both windage and elevation adjustment and the A3 and A4 incorporate a flat top picatinny rail? A2 + Flat Top doesn't compute.
A3 was a full-auto Navy variant that shouldn’t even be referred to because they were built on A2 and A4 uppers.