Sons of Liberty SPR Barrel: Accuracy Tested with 30-Shot Groups + A-ZED Score

Published on January 28, 2025
Duration: 16:49

This video provides an in-depth accuracy test of the Sons of Liberty Gunworks 16-inch SPR barrel, featuring unique polygonal rifling and a 5/8x24 thread pitch. The instructor conducts 30-shot groups with various ammunition types, meticulously recording data on velocity, rifle stability, and group size using advanced metrics like the A-ZED score. The results demonstrate exceptional accuracy, positioning the barrel favorably against competitors.

Quick Summary

The Sons of Liberty Gunworks 16-inch SPR barrel features unique 3-groove polygonal rifling and a 5/8x24 thread pitch. Accuracy tests with 30-shot groups showed exceptional performance with match ammunition, achieving a 1.263 MOA group with Hornady 73gr ELD Match and a 1.319 MOA group with Berger 77gr Match, resulting in high A-ZED scores.

Chapters

  1. 00:00Introduction: Sons of Liberty SPR Barrel
  2. 00:10Barrel Specifications Overview
  3. 01:10Bench Inspection: Borescope & Measurements
  4. 02:22Rifle Setup and Range Preparation
  5. 03:16Testing Methodology: 30-Shot Groups
  6. 03:43Group 1: PMC Bronze 55gr FMJ Results
  7. 06:02Group 2: Hornady 73gr ELD Match Results
  8. 07:37Group 3: Berger 77gr Match Results
  9. 09:46Overall Results & A-ZED Score Explained
  10. 12:04Comparison to Other Tested Barrels
  11. 12:51Deep Dive: Understanding the A-ZED Score
  12. 16:38Conclusion and Final Thoughts

Frequently Asked Questions

What are the key features of the Sons of Liberty Gunworks SPR barrel?

The Sons of Liberty Gunworks 16-inch SPR barrel features 3-groove polygonal rifling, a 5/8x24 thread pitch (uncommon for AR-15s), a .223 Wylde chamber, 416R stainless steel construction, a 1:7 twist rate, and a .074-inch gas port.

How does the A-ZED score measure barrel accuracy?

The A-ZED (A-Zone Equivalence Distance) score estimates the maximum distance a barrel can consistently group shots within a USPSA A-Zone. It's calculated by multiplying the mean radius of a 30-shot group by four and determining the distance where this theoretical spread equals 5.91 inches.

What ammunition was used to test the Sons of Liberty SPR barrel's accuracy?

The barrel was tested with three types of ammunition: PMC Bronze 55-grain FMJ, Hornady 73-grain ELD Match, and Berger 77-grain Match. The match-grade loads demonstrated significantly better accuracy.

What were the overall accuracy results for the Sons of Liberty SPR barrel?

The barrel performed exceptionally well, especially with match ammunition. The Hornady 73gr load yielded a 1.263 MOA 30-shot group with a mean radius of 0.299 MOA, and the Berger 77gr load produced a 1.319 MOA group with a 0.320 MOA mean radius, both achieving high A-ZED scores.

More Range & Competition Videos You Might Like

More from Preston Moore

View all →