AR15 A2 rear sight, and BZ0

[yankytrash]

In the Army Manual for setting the BZ0 it describes the Marine Corps technique for 25-meter zeroing.

It states:
4 ROTATE ELEVATION KNOB IN THE DOWN DIRECTION (COUNTER-CLOCKWISE).
THE ELEVATION KNOB SHOULD STOP THREE CLICKS PAST THE 300-METER
MARK. THE REAR SIGHT SHOULD BE ALL THE WAY DOWN ON THE LAST
WHOLE “CLICK” BEFORE IT BOTTOMS OUT. THIS IS CALLED MECHANICAL
ZERO ELEVATION FOR THE REAR SIGHT. IF YOUR RANGE SCALE WILL NOT
LINE UP IN THE ABOVE MANNER, AN ARMORER WILL BE REQUIRED TO
ADJUST THE RANGE SCALE FOR YOU.
Well, what if it won't go a full 3 clicks under 300m? Mine only gets 2 clicks past 300m. Is this wrong? Are my ranges supposed to be off, if this is the case?

How do you fix it?

[Alexis Machine]

You using a flattop with removable carry handle/sights?

[KenBerry]

There is an adjustment for the A2 rear sight settings, you just need an allen wrench.

http://communities.msn.com/TheMarylandAR15ShootersSite has a whole section on different zeroing methods that you should take a look at.

The also have a manuals section which includes links that'll get you to the AR15 armorers manuals which have instructions on adjusting the rear sight.

Since you are already set to bottom out at -2 you may want to consider using the "Improved Battlesight Zero". It provides a much flatter trajectory out to 200 meters, which is the range that most ARs are used at anyway.

[yankytrash]

Alexis - No sir. Integral handle A2.

Ken - Probably the best collection of informaiton about an AR I've ever seen. Thanks man.

[Bruegger]

Yanky – when I was in, the Corps zeroed the A2 at 36 yards, not 25 meters, and we did it with the rear sight set to “8/3” for a 300 yard BZO.

The near zero at 36 yards = the far zero at 300, so if you zero the rifle at 36 yards, your sights will be calibrated for bullet drop for all ranges on the rear sight (assuming you use military ammo or the equivalent). Using this method, the proper setting for 200 yards is then “8/3 minus 2 [clicks].”

This method is so simple it’s just about Marine proof. With a 300 yard BZO, you should be about 4” high at 200, which is just fine for a battlesight setting.

Semper fi,
Bruegger out.