100-Yard Zero for AR

BACKGROUND

First, some background information on the rifle and optic. With an AR, the optic sits significantly higher than the barrel of the rifle. This is called height over bore. When a round is fired, it has an upward trajectory, hits its apex, and then comes down. This is where the concept of two zeroes on the AR comes from. When we use an AR for personal defense or as one of our home-defense weapons, we’re not as concerned with the far-distance zero as we are with the first impact of the round as it exits the barrel and heads upward.

CHART FOR ZEROING AN AR RIFLE

Deryck displays a chart that shows four different zeroes: 15, 50, 100, and 200 yards. The other side shows the distance to the target, also in yards: 5, 10, etc. up to 200. For personal and home defense, we’re mainly concerned with 5, 10, and 25 yards distance to the target. The chart shows where the bullet will impact with each zero and the target at each of the distances—either above or below the point of aim.

WHY THE 100-YARD ZERO?

Deryck talks about over holds and under holds with the various zeroes. With the 100-yard zero, from 5 to 200 yards, there are no under holds that we need to remember to make sure the bullet we fire doesn’t go high, miss the bad guy, or maybe hit something we don’t want to hit. In rifle training classes, we don’t have to worry about the round going high and over the berm.

This is why he uses and recommends zeroing an AR rifle at 100 yards.

Questions? Put them in the comments and Deryck will get back to you.