Understanding MOA vs MRAD in Rifle Scopes
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: 1 MOA corresponds to about 1.047 inches at 100 yards. For every 100 yards of distance, the adjustment for 1 MOA moves the point of impact roughly 1.047 inches in the direction you adjust (up, down, left, or right).
- 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.
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Adjustment: MOA-based scopes typically allow for adjustments in 1/4 MOA or 1/2 MOA per click (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. It is a metric-based system compared to MOA.
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How it works: MRAD is metric 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.
- 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.
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Adjustment: MRAD-based scopes usually allow adjustments in 0.1 MRAD increments, meaning each click moves the reticle by about 1 cm at 100 meters or 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 |
| 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 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 simplicity with metric measurements and ease of calculation when making range corrections. Favored for finer adjustments over long distances.
Conclusion:
- MOA uses a traditional imperial system (inches) for adjustments.
- MRAD uses the metric system (centimeters and millimeters) and is often regarded as more precise and easier for long-range shooting.
Both systems can be accurate and effective; it just depends on which unit of measurement you're more comfortable using.