Basic Rifle Marksmanship Series: Part II(B) - Aperture Sights

Before we begin today's lesson, please take a few minutes to review our previous discussions on safety and the use of open sights.

Aperture sights, sometimes called "peep" sights, are a relatively recent innovation in iron sight technology. First fielded en masse with the British Pattern 14 rifle, American soldiers encountered the peep sight with the P14's American cousin, the M1917 Enfield. Its superiority over open sights for both reactive and deliberate fire has made the aperture sight a standard on American miltary longarms since then, including today's M16/M4 rifle/carbine system.

The aperture itself is housed on the rear of the rifle's receiver, with the center of the sight's circular opening being parallel with the centerline of the rifle's bore. In using the aperture, the shooter looks through the center of the opening and concentrates on the front sight, per the diagram above.

With the proper focus, the shooter does not see the aperture itself. Instead, the aperture forms the frame for the rifle's front sight, which is then placed properly on the target:
You'll notice in both diagrams that the front sight post is centered exactly in the middle of the aperture. Failute to achieve and maintain this centered front sight post will lead to elevation errors (due to the front sight post being too high or too low) or windage errors (due to the front sight post being skewed to the left or right of center aperture).

That's today's lesson - short and sweet. Remember to look through, not at the aperture, keep the front sight post centered in the opening, and you'll have this lesson mastered in no time.

Until next time....