How to Measure Group Size on the Range (MOA Method)

‍

Why Group Size Matters in Shooting

Group size is a way to evaluate the precision of your rifle, ammunition, and shooting fundamentals. Understanding how to measure this properly using Minute of Angle (MOA) allows you to track progress, compare setups, and make informed decisions at the range.

What Is MOA?

• MOA (Minute of Angle) is an angular measurement.
• At 100 yards, 1 MOA = 1.047 inches, commonly rounded to 1 inch for ease.
• It's used to describe how far apart your shots land on a target and gives a standardized way to evaluate accuracy.

What You’ll Need

• Digital Calipers: Essential for precise measurements.
• Paper Target: Preferably with a grid or 1 MOA marks.
• Knowledge of Bullet Diameter: For example, a 6.5 Creedmoor typically measures 0.264 inches.

How to Measure Group Size in MOA

There are two primary methods to measure group size. Both are valid and will give nearly identical results if done correctly.

Method 1: Outside-to-Outside Minus Bullet Diameter

This is the method shown in the video and one I use regularly. If you have digital calipers, the method is very simple

Steps:

1. Shoot a Group: Typically 3 to 5 rounds.
2. Measure Bullet Diameter: Use calipers to determine this ahead of time.
3. Zero Calipers: Once you have the bullet diameter, without changing the digital readout, zero your calipers so it reads 0.00 with bullet diameter still present on the caliper. If you completely close the calipers the measurment would read in the negative.
4. Measure Group: Find the two bullet holes that are farthest apart and measure from outside edge to outside edge.
5. True reading: Now the measurement you calipers give you includes deducting the diameter of the bullet giving your measurement in either MOA or MIL's depending on your settings

Method 2: Center-to-Center

• Instead of subtracting bullet diameter, estimate and measure from the center of one hole to the center of the furthest.
• Slightly harder to do without tools or training, but effective.

Real Example from the Range

• Rifle: Benelli Lupo (Chaos)
• Optic: Zeiss Conquest V4 (6–24x50)
• Ammo: Federal Fusion, 6.5 Creedmoor
• Distance: 100 yards

Results:

• 5-shot group (cold bore included):
  • Measured at 1.29 inches
  • Minus 0.264 bullet diameter = 1.026 inches ≈ 1 MOA
• Excluding Cold Bore Shot:
  • Measured at 0.613 inches ≈ 0.6 MOA

Additional Notes for New Shooters

• Start at 100 yards: Makes MOA math easier to understand.
• Use consistent methods: Track your shooting improvements more reliably.
• Cold bore vs. follow-up shots: Decide in advance whether to include the cold bore shot based on your purpose (e.g., hunting vs. benchrest shooting).

Summary

Measuring MOA group size is a practical skill that helps shooters of all levels understand their firearm's performance. Whether you're dialing in a hunting rifle or testing new loads, being able to evaluate your group size with consistency will support better decision-making and steady improvement.

‍