First groups with The Lump

Published on July 15, 2018
Duration: 7:12

The video details initial accuracy testing of an AR-10 platform chambered in 6.5 Creedmoor, focusing on the impact of added weight on barrel harmonics. The presenter shares results from shooting two five-shot groups with a heavy muzzle device, achieving a best group of 0.675 inches at 100 yards. This performance is compared favorably to previous suppressed shooting results, suggesting potential for accuracy improvement with added weight. The presenter also discusses ammunition and brass choices, including IMR 4451 powder and Starline small primer brass, and mentions a scope issue that prevented testing of a 6mm PPC rifle.

Quick Summary

Testing an AR-10 in 6.5 Creedmoor with a heavy muzzle device ('the lump') yielded impressive results, with the best 100-yard group measuring 0.675 inches. This accuracy rivals previous performance with a suppressor, suggesting that added barrel weight can positively influence harmonics and overall precision.

Chapters

  1. 00:00Introduction & Powder Shortage
  2. 00:53New Powders & Muzzle Devices Arrive
  3. 01:44Testing 'The Lump' on the AR-10
  4. 02:00Range Session Begins
  5. 03:21Accuracy Results: Group Sizes
  6. 04:05Analysis: Weight vs. Suppressor Accuracy
  7. 04:50Ammunition & Brass Stock Update
  8. 06:03Bad News: Broken Scope
  9. 06:45.223 Video Preview
  10. 07:03Conclusion

Frequently Asked Questions

What were the group sizes achieved with the heavy muzzle device on the AR-10?

During the test, two five-shot groups were fired at 100 yards. The first group measured 0.766 inches, and the second, best group of the session, measured 0.675 inches. This performance is comparable to previous results with a suppressor.

How does adding weight to the barrel affect accuracy in this AR-10 6.5 Creedmoor test?

The test suggests that adding significant weight to the barrel, via a heavy muzzle device referred to as 'the lump,' can positively impact accuracy. The achieved group sizes were comparable to, and potentially better than, those shot with a suppressor, indicating a beneficial effect on barrel harmonics.

What ammunition components are being used and tested for the 6.5 Creedmoor?

The presenter is testing IMR 4451 powder with 140-grain Hornady Match boat tail hollow point bullets. They also mention ordering Shooters World powders for future testing and have had excellent results with Starline small primer brass.

What issues prevented testing of the 6mm PPC rifle?

The planned testing of the 6mm PPC rifle was halted due to a broken crosshair discovered in a fixed 36x Weaver scope. The presenter intends to contact Weaver for repair options, but anticipates it may not be a free service.

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