Live Q&A - January 5, 2021

Published on January 6, 2021
Duration: 65:55

This Q&A session addresses common AR-15 tuning issues, particularly over-gassing by manufacturers. The expert explains that manufacturers over-gas to accommodate a wide variety of ammunition, but this can lead to reliability problems, especially with suppressed or short-barreled rifles. Tuning involves adjusting buffer and spring weights, but optimal reliability is best achieved by selecting a specific ammunition type and tuning the system to it. The discussion also touches on LMT enhanced bolts, gas system lengths, and the nuances of polygonal rifling.

Quick Summary

Manufacturers often over-gas AR-15 barrels to ensure reliability across a wide range of ammunition. For optimal performance, especially with suppressed or short-barreled rifles, it's best to select a specific ammunition type and tune the rifle's gas system and buffer setup to that round.

Chapters

  1. 00:00Introduction and Welcome
  2. 02:00Q&A Session Begins
  3. 03:09Triarc Systems Barrels and SCP Rifling
  4. 03:43Addressing Over-Gassed Barrels
  5. 04:10Tuning for Mark 18 and 12.5-inch Builds
  6. 05:05Gas System Tuning for Specific Ammunition
  7. 06:01LMT Factory Rifles and Buffer Weights
  8. 07:22LMT 20-inch 5R Barrel and Enhanced Bolt
  9. 08:04Mid-Length vs. Carbine Gas Systems
  10. 08:18Loose Upper/Lower Fit and Functionality
  11. 09:14Bullpup Rifle Preferences
  12. 09:22Steyr SP9A3 Delay Blowback
  13. 10:00Thoughts on the Book 'Misfire'
  14. 10:26Sharps Rifle Company Bolt Review
  15. 11:37LMT .338 Norma Magnum or .277 Fury?
  16. 12:44Centurion Barrel Production Update
  17. 13:49LWRC IC-DI 5.56 Review
  18. 14:42KE Arms KP-15 Monolithic Polymer Lower
  19. 15:35AK Platform and Suppressors
  20. 16:32Polygonal Rifling in Rifle Barrels
  21. 17:33Button Rifling vs. Polygonal Rifling
  22. 18:14ARMS Rings and Mounts
  23. 19:30LMT Torque Wrench and Bolt Breakage
  24. 20:22POF Buffer Tube for Caracal 816
  25. 21:00LMT Q&A Mention
  26. 21:09AR-57 Upper Receiver
  27. 21:51Kel-Tec P50 Thoughts
  28. 22:20B&T APC 9K Review
  29. 22:50Bayonet Lug vs. Rail Length
  30. 23:57Metallurgy in Firearms Manufacturing
  31. 24:55ACOG TA01 vs. Elcan C79
  32. 25:21DSA Heavy Barrel FAL
  33. 26:01LMT 6.8 SPC Chamber and SPC II
  34. 27:36Patch Sales Update
  35. 29:05Glock 22 Gen 5 Thoughts
  36. 30:57Colt LE6940 Barrel Replacement
  37. 32:07Ammunition Stock and Testing
  38. 32:30Audio and Lighting Improvements
  39. 32:57Chris and SAS Mentions on Other Channels
  40. 33:47Knight's Armament Non-Proprietary AR-15
  41. 34:08BCM 6.5 Creedmoor and .308
  42. 35:05Charisma vs. Wisdom in Content
  43. 35:16Cobra Kai and Eagle Fang
  44. 36:02Glock Two-Pin Design on Gen 5
  45. 37:11PTR-9 Review
  46. 37:47Geissele URGI Upper Receiver Review
  47. 38:36Silent Captured Recoil Buffer Springs
  48. 40:00Buffer/Spring Combo for 7.62x39 AR
  49. 41:41Rare Breed Triggers Discussion
  50. 42:54Black and White Poster
  51. 44:03Rare Breed Forced Reset Triggers
  52. 45:41Defense Ammo for 11.5-inch AR and Pistol
  53. 47:0340 S&W as a Suppressor Round
  54. 48:33Pets and Animals
  55. 49:16AR Platform Robustness for Big Bore Cartridges
  56. 50:53JP Variable Mass BCG
  57. 52:00TV Series Recommendations
  58. 52:32Gas System Lengths and Port Sizes
  59. 56:23Centurion vs. FN Barrel Twist Rate
  60. 57:26Colt AR-15A4 Release
  61. 58:15Extractor Longevity on 7.62x39 AR
  62. 59:15Teenage Work Ethic and Jobs
  63. 60:00Piston Life in LWRC Rifles
  64. 61:14IWI 5.45x39 Galil ACE
  65. 62:26Glock Cleaning and Maintenance Video
  66. 63:10Mark 262 vs. M855A1 for US Army
  67. 64:36Patch Order Information
  68. 65:33Patch Shipping Update
  69. 65:57Closing Remarks

Frequently Asked Questions

Why do AR-15 manufacturers over-gas barrels?

Manufacturers often over-gas AR-15 barrels to ensure reliable function across a wide range of ammunition, from weak to strong loads. This approach accommodates diverse ammo performance but can lead to excessive gas pressure and recoil, especially with full-power rounds or in suppressed/short-barreled configurations.

How can I tune an over-gassed AR-15 for better reliability?

Tuning an over-gassed AR-15 typically involves adjusting buffer and spring weights. For optimal reliability, it's best to select a specific ammunition type and then tune the rifle's gas system and buffer setup to that particular round, rather than trying to make it work universally.

Is polygonal rifling good for rifle barrels?

Polygonal rifling is excellent for machine guns due to its longevity and ease of cleaning. However, for precision rifle barrels, traditional button rifling with sharp edges is generally preferred for achieving higher accuracy.

Why does the US Army use M855A1 over Mark 262?

The US Army chooses M855A1 over Mark 262 primarily for cost-effectiveness and its capability as a general-purpose round with barrier penetration. Mark 262 is an anti-personnel round designed for precision, lacking the necessary penetration characteristics for military applications like barrier engagement.

What is the best buffer and spring combo for a 16-inch AR in 7.62x39?

For a 16-inch AR chambered in 7.62x39, an H2 buffer is often a good starting point, especially without an adjustable gas block. The wide pressure variance in 7.62x39 ammunition makes tuning more complex than with standard 5.56 NATO, requiring careful buffer selection.

Related News

All News →

More Reviews Videos You Might Like

More from SmallArmsSolutions

View all →