i'm a novice, putting together my first ar.
someone  ?? please, explain the difference between a a2 a3 a4 flat top.
i have a a3 upper on the way.
need to know what kind of rear sight to order
 rra a3 flat top.
               any and all info. appriciated
                                                              thanks
                                                              metco
                                                                   ed

You might find the ARMs #40L SP an excellant sight.



I Sure Love mine.

As for A2, A3 and A4... A2 is the Military Designation for the fixed Carry Handle model, A3 is a manufacturer (like Bushmaster) designation for a flattop, and A4 is the Military Designation for the the M16 with Flattop, removable front sight, and A knights Full length rail.

Hope that helps.

Nathan

NATHAN,
 THANKS!!!
is there a diff. in the height of a a2,a3,a4 ????????????
                                                metco
                                                   ed
!!!!!!!!!!!!!!!!!! I NOW UNDERSTAND  THANKS,    ED

There is NO height difference.  

A2 upper:


A3/A4:

 THANKS TO ALL !!!!!
                          metco
                             ed