MOA and MRAD
When it comes to MOA and MRAD in the context of rifle scopes, these are two different units of angular measurement used to adjust the point of impact (POI) of the crosshair or reticle in a scope. Both of these systems are used to make windage (left/right) and elevation (up/down) adjustments when zeroing a scope or compensating for bullet trajectory over distance.
Here’s how they differ:
1. MOA (Minute of Angle)
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Definition: MOA is an angular measurement that is based on the geometry of a circle. One minute of angle is equal to 1/60th of a degree, or approximately 1.047 inches at 100 yards.
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How it works: The key point to understand is that 1 MOA corresponds to about 1.047 inches at 100 yards. This means that for every 100 yards of distance, the adjustment for 1 MOA will move the point of impact roughly 1.047 inches in the direction you adjust (up, down, left, or right).
- For example:
- At 100 yards: 1 MOA = 1.047 inches
- At 200 yards: 1 MOA = 2.094 inches
- At 300 yards: 1 MOA = 3.141 inches
- And so on.
- For example:
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Adjustment: MOA-based scopes typically allow for adjustments in 1/4 MOA or 1/2 MOA per click (meaning each click moves the reticle by 0.25 or 0.5 inches at 100 yards).
2. MRAD (Milliradian)
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Definition: MRAD (or Mil for short) is another angular unit used in long-range shooting. A milliradian is 1/1000th of a radian, which is a standard unit of angular measurement. It’s a more metric-based system compared to MOA.
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How it works: MRAD is based on the metric system and represents a smaller unit of angle. 1 MRAD corresponds to 10 centimeters (about 3.94 inches) at 100 meters, or roughly 3.6 inches at 100 yards.
- For example:
- At 100 meters (or 100 yards): 1 MRAD = 10 cm (about 3.94 inches)
- At 200 meters: 1 MRAD = 20 cm
- At 300 meters: 1 MRAD = 30 cm
- And so on.
- For example:
-
Adjustment: MRAD-based scopes usually allow adjustments in 0.1 MRAD increments, which means each click of the turret typically moves the reticle by 0.1 MRAD (about 1 cm at 100 meters or about 0.4 inches at 100 yards).
Key Differences:
| Feature | MOA (Minute of Angle) | MRAD (Milliradian) |
|---|---|---|
| Unit of Measure | Angle (1/60th of a degree) | Angle (1/1000th of a radian) |
| Distance (100 yards) | 1 MOA ≈ 1.047 inches | 1 MRAD ≈ 3.6 inches (100 yards) |
| Common Adjustments | 1/4 MOA, 1/2 MOA | 0.1 MRAD, 0.5 MRAD |
| System Type | Imperial-based, easier for some hunters | Metric-based, easier for precision shooters |
| Ease of Use | May require more math for long-range adjustments | More consistent at various distances, easier with metric system |
| Common Usage | Typically used by hunters in the U.S. | More common among military and tactical shooters |
Conversion:
To convert between MOA and MRAD:
- 1 MOA ≈ 1.047 inches at 100 yards = approximately 2.91 cm at 100 meters.
- 1 MRAD ≈ 3.6 inches at 100 yards = approximately 10 cm at 100 meters.
Which is Better?
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MOA: Often preferred by hunters and those using imperial measurements because it’s easier to think in terms of inches. MOA is widely used in North America, especially for sporting and hunting purposes.
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MRAD: Preferred by military, tactical, and long-range precision shooters due to its simplicity with metric measurements and ease of calculation when making range corrections in metric units. It’s also favored in disciplines that require finer adjustments over longer distances.
Conclusion:
- MOA uses a more traditional imperial system (inches) for adjustments.
- MRAD uses the metric system (centimeters and millimeters) and is often regarded as more precise and easier to work with for long-range shooting.
Both systems can be accurate and effective; it just depends on which unit of measurement you're more comfortable using.