Whats the best rear sight for an A4 CAR length upper? Will any do? Or are there certain ones made for certain length gas system? Sorry about the noob essence to this queston but it would be real nice if someone would educate me on how the different lengths matter.
Because Ive seen sights that say they are for CAR systems and others for Rifle lengths:confused:
I somewhat understand why but I would benefit from someone putting it in plain ol english for me.:p Thanks

