KAC SR-15 MOD2 PHYSICAL

Published on December 30, 2021
Duration: 33:38

This video provides an in-depth physical inspection of a Knight's Armament SR-15 Mod 2 rifle, highlighting its unique design features and proprietary components. The instructor demonstrates specialized tools and techniques required for working on KAC firearms, emphasizing differences from standard AR-15 platforms. Key areas covered include the bolt and barrel extension design, gas system, ambidextrous lower receiver, bolt carrier group specifics, and various dimensional checks for headspace, throat erosion, and alignment.

Quick Summary

The Knight's Armament SR-15 Mod 2 features unique 'flower petal' bolt lugs and proprietary components like the firing pin and cam pin, enhancing ruggedness. Specialized tools are required for maintenance due to its distinct bolt and barrel extension design, differing significantly from standard AR-15 platforms.

Chapters

  1. 00:00Introduction & KAC Tooling
  2. 01:14Gas System Overview
  3. 02:10Lower Receiver Ambidextrous Features
  4. 02:43Bolt Carrier Group Disassembly
  5. 04:53Unique KAC Bolt Features
  6. 05:30Firing Pin Protrusion Check
  7. 06:14Proprietary Cam Pin Analysis
  8. 07:12Magnetism Check
  9. 07:36Bolt Tail Check
  10. 07:49Carrier Length Measurement
  11. 08:12Bolt Support Shoulder Measurement
  12. 08:47Bolt Face & Firing Pin Hole Checks
  13. 09:32Extractor Removal & Analysis
  14. 10:35Bolt Face Check
  15. 11:09Carrier Key (Gas Key) Check
  16. 12:00Bolt Shoulder Support & Gas Ring Run
  17. 12:29Bolt Tail Run Measurement
  18. 13:42Bolt Carrier Group Complete
  19. 13:54Gas System Path Check
  20. 14:11Gas Tube Alignment
  21. 14:43Gas Tube Obstruction Check
  22. 15:22Headspace Check
  23. 16:59Throat Erosion Check
  24. 18:24Muzzle Erosion & Straightness
  25. 18:55Feed Ramp Inspection
  26. 19:49Upper Receiver & Rail Alignment
  27. 20:50Muzzle Device & Thread Runout
  28. 21:22Lower Receiver - Buffer & Spring
  29. 22:09Carrier Travel Gap
  30. 22:59Magazine Well Check
  31. 23:28Upper/Lower Receiver Fitment
  32. 24:15Pivot & Take Down Pin Areas
  33. 24:34Trigger Pull & Fire Control Group
  34. 25:43Hammer & Trigger Pin Gauging
  35. 26:31Castle Nut & Receiver Extension Alignment
  36. 29:36Borescope Setup
  37. 29:42Bore & Crown Inspection
  38. 30:38Gas Port Inspection
  39. 31:18Chamber & Throat Inspection
  40. 32:19Test Firing & Brass Inspection
  41. 33:32Conclusion

Frequently Asked Questions

What specialized tools are needed for a Knight's Armament SR-15 Mod 2?

Working on KAC firearms requires specialized tools like a KAC-branded reaction rod due to unique bolt and barrel extension designs. Standard AR-15 tools may cause damage, so it's crucial to use KAC-specific or compatible equipment for disassembly and maintenance.

How does the KAC SR-15 Mod 2 bolt differ from a standard AR-15 bolt?

The KAC SR-15 Mod 2 bolt features a distinctive 'flower petal' lug arrangement, unlike the squared-off lugs on standard AR-15 bolts. This design, along with a proprietary cam pin, contributes to increased ruggedness and durability.

What are the key inspection points for a KAC SR-15 Mod 2 gas system?

The KAC SR-15 Mod 2 gas system uses a keyed setup with a miniature castle nut. Inspections focus on ensuring a clear gas path, proper gas tube alignment within the upper receiver, and checking for any obstructions. The gas block itself is secured differently than on standard AR-15s.

What is the typical trigger pull weight for a Knight's Armament SR-15 Mod 2?

The trigger pull weight on a Knight's Armament SR-15 Mod 2 typically breaks around 5 pounds. The first stage of the pull is approximately 3.5 pounds, offering a crisp break for accurate shooting.

Are the components of a KAC SR-15 Mod 2 interchangeable with standard AR-15 parts?

No, the KAC SR-15 Mod 2 utilizes proprietary components, including the firing pin, cam pin, extractor, and bolt. These parts are not interchangeable with standard AR-15 parts and require KAC-specific replacements for maintenance or repair.

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