How To Zero The AR15A4 / M16A2 / M16A4: Dial In The Rear Drum For Distance

Published on August 11, 2020
Duration: 11:11

This video provides a comprehensive guide to zeroing and utilizing the A2/A4 rear sight drum on AR-15 and M16 platforms. It details how to calibrate the elevation drum using a 1/16 inch Allen key and explains the function of the dual apertures for different ranges. The demonstration covers achieving a 25-yard zero for a standard military configuration and testing the sight's effectiveness at longer distances.

Quick Summary

To zero the A2/A4 rear sight drum on an AR-15 or M16, first establish a 25-yard zero for point of aim/point of impact. Then, use a 1/16 inch Allen key to calibrate the elevation drum, aligning its markings with the sight's reference point to match your desired range settings.

Chapters

  1. 00:00Introduction to A2/A4 Sight Zeroing
  2. 00:45Understanding Rear Sight Controls (Windage & Elevation)
  3. 01:13Dual Aperture Explanation (0-200 Yards vs. Precision)
  4. 02:00Calibrating the Elevation Drum with Allen Key
  5. 04:18Improved Battle Sight Zero (IBSZ) Method
  6. 05:22Live Fire Zeroing at 25 Yards
  7. 07:20Long Range Testing at 390 Yards

Frequently Asked Questions

How do you zero the A2/A4 rear sight drum on an AR-15 or M16?

Zeroing involves establishing a point of aim/point of impact at a specific distance, typically 25 yards for a standard military zero. You'll use the front sight post for initial elevation and then calibrate the rear sight's elevation drum using a 1/16 inch Allen key to match your desired range settings.

What is the purpose of the dual apertures on the A2/A4 rear sight?

The A2/A4 sight has two apertures: a larger one marked '0-2' for close distances (0-200 yards/meters) and a smaller, precision aperture for longer ranges. The larger aperture is intentionally set lower to compensate for bullet drop at closer distances.

How do you adjust the elevation on an AR-15 A2 carry handle sight?

Elevation is adjusted using the drum located at the bottom of the rear sight assembly. You can rotate this drum to select different range settings (e.g., 300-800 meters). For initial zeroing and calibration, a 1/16 inch Allen key is used to align the drum's markings with the sight's reference point.

What is an Improved Battle Sight Zero (IBSZ) for an AR-15?

An IBSZ is a zeroing method that provides versatility. It typically involves adjusting the rear sight drum to achieve a 50/200 yard or 100-meter zero. This allows the shooter to hold center mass on targets from close range out to 200 yards with the same sight setting.

Related News

All News →

More Training & Techniques Videos You Might Like

More from Mrgunsngear Channel

View all →