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  • Post last modified:February 28, 2023

In this article, let's explain what improved and revised improved battlesight zeros are, how they work and discuss if modern-day red dot shooters can benefit from learning the old school A2/A4 rear iron sight.

What Is Improved Battlesight Zero (RIBZ)?

rear iron sight 8 3 battlesight zero

Improved Battlesight Zero works with the standard 6/3 and 8/3 carry handle style rear iron sights in with A frame front sight post - Designed for 25 or 300 meters zero.

The 8/3 carry handle has 2X clicks of the 6/3 carry handle

If you have not used an old school M4 carry handle sight, here is how it works:

Elevation Adjustment

8 3 battlesight elevation drum

Do this first:

Lower the elevation drum all the way down and up just one click past the 300 mark for an A1 carry handle rear sight.

Lower the elevation drum all the way down and up 2 clicks to line up the etched letter "Z" for 8/3 or A4 rifle with removable carry handle (0.5 MOA / click).

Position yourself in a solid shooting position for zeroing and only adjust the front sight for elevation

Windage Adjustment

ar15 sight picture

The standard A2 rear sight has a 32-pitch screw, and that's equivalent to half-minute-of-angle (moa) graduations per click.

Center the windage knob to the middle marking, and use the smallest aperture to align the front sight post to start the zeroing process.

It's imperative to line up those two as perfect as possible otherwise any head movement will introduce a different sight picture and the shooter will have inconsistent groups down range.

Fact: This is why parallax free optics are so helpful so the shooter can shoot much more accurately without having to perfectly align iron sights.

Zeroing Example

m4 zeroing

Use MOA grid targets to make counting MOA adjustments much easier than with a ruler.

At 50 yards, after the first 3 shot group, go down range to measure the the distance between the shot group and the point of aim.

Example 1: Missing 2" to the left an 4" low

Adjustment Ratio: At 50 yards, 1 click = 0.25 MOA

Front Sight Elevation Adjustment:

  • 4 Detents = about 1.25 MOA per click (most modern sights) - 6.4 Clicks up
  • 5 Detents = about 1 MOA per click (M16A1 front sights) - 8 Clicks up

Do not change this rear sight elevation. Use the front sight post only to make changes in elevation while zeroing.

Windage Adjustment: Do not adjust the rear sight elevation! only the rear sight windage

For more information, please check out Army/USMC battlesight zero procedure - TM9-1005-319-10 M16/M4 operator's manual.


What's Revised Improved Battlesight Zero?

how to add revised improved battlesight zero on 8 3 rear iron sight

The advantage of the RIBZ zero sighting scheme is to add the 100 yd zero capability setting to the rear sight.

Learn how to do this by watching this video:

We do that by accessing the index screw to loosen with the 1/16” allen wrench to make the necessary alteration to the elevation drum to make RIBZ 100, 50/200 & 300 available.

We recommend checking out this awesome test document regarding this topic from Calguns.net Click here to view

100 Yard Setting

RIBZ sight setting

Starting with the elevation drum at the 8/3 setting, turn the elevation drum counter-clockwise 3 clicks (8/3, -3) for the 100 yard point of aim equals point of impact setting.

Remember: The 8/3 carry handle has 2X clicks of the 6/3 carry handle

[6/3 -6] for 6/3 style rear sight at 100yd

50 Yard

If you want to go back to the Improved Battlesight Zero, simply set the elevation drum to 8/3, -2 and you're good to go for a 50 yard / 200 yard zero.

[6/3 - 4] for 6/3 style rear sight at 50 yd

300 Yard Setting

To use the standard military 300 meter setting , just set the elevation drum back to 8/3.

Other Considerations

Eotech in action

Different variations in:

  • Sight height above the bore
  • Barrel length
  • Bullet velocity
  • Bullet weight
  • Bullet type

These factors can affect the impact point even with the same point of aim. Test and narrow down your ammo for consistent results.

EOTECH exps3 reticle outdoor

Can Modern Day Red Dot Shooters Benefit From This?

Learning about modern aiming technology can improve your shooting skills and appreciation for the craft. If you're not interested, our red dot guide can help you achieve accurate aiming without the hassle of iron sights.

Using a red dot with a powerful weapon light is more effective than iron sights for night shooting. Zeroing the red dot at 36 yards can help you hit targets accurately between 10 to 300 yards without worrying about holdover.

Give it a try and see the difference in shot group size for fast and effective aim.