Understanding Minute of Angle (MOA) in Firearm Optics
When it comes to precision shooting and firearm optics, few concepts are as fundamental — and sometimes misunderstood — as the minute of angle, commonly abbreviated as MOA. Whether you’re a seasoned marksman dialing in your rifle at long range or a novice trying to understand your scope’s turrets, understanding MOA is crucial for accurate shooting.
What is a Minute of Angle?
A minute of angle is a unit of angular measurement. Just as a circle is divided into 360 degrees, each degree is further divided into 60 minutes. Therefore, one minute of angle is 1/60th of one degree.
While that might sound like a concept more at home in a geometry class, it has very real applications in shooting. Because MOA is an angular measurement, it describes how much your bullet impact will move relative to your point of aim as distance increases.
How MOA Translates to Distance
At 100 yards, 1 MOA equals approximately 1.047 inches. For practical purposes, most shooters round this to 1 inch at 100 yards. This makes the math simpler and is accurate enough for most shooting applications.
Here’s how that scales:
- 1 MOA ≈ 1 inch at 100 yards
- 1 MOA ≈ 2 inches at 200 yards
- 1 MOA ≈ 10 inches at 1,000 yards
So, if your bullet is hitting 2 inches high at 100 yards, you would adjust your scope by about 2 MOA down to bring your point of impact back in line with your point of aim.
MOA in Scopes and Adjustments
Most rifle scopes designed for precision shooting have turrets calibrated in 1/4 MOA per click. That means for each click of the elevation or windage turret, you’re moving the point of impact roughly 0.25 inches at 100 yards.
If your scope is zeroed at 100 yards and your bullet hits 2 inches left of the target, you’d adjust 8 clicks (2 inches / 0.25 inches per click) to the right to center your shot.
Some scopes, especially those built for military or long-range applications, might use 1/8 MOA increments for finer adjustments, while others might use MILs (milliradians), which is a different angular system.
MOA and Group Sizes
Shooters also use MOA to describe the accuracy potential of a rifle. For example, a rifle that can consistently shoot 1-inch groups at 100 yards is said to be a 1 MOA rifle. This is a way to measure consistency and precision, not just scope adjustment.
- Sub-MOA: Rifles that group under 1 inch at 100 yards are often marketed as “sub-MOA,” indicating a high level of precision.
Final Thoughts
Minute of angle is a cornerstone concept in the world of firearm optics. It ties together angular measurement, distance, and scope adjustment into one practical system that shooters use every day. By understanding MOA, shooters can make precise corrections, measure their groups, and stretch their accuracy to new distances with confidence.
Whether you’re zeroing your scope at the range or compensating for wind and elevation at 800 yards, MOA is the language your optic speaks — and now, you do too.