3-Round Limiter Compatibility Test | C.A.R.L for Super Safeties

Published on February 26, 2026
Duration: 7:45

This video from Desk Pop demonstrates a compatibility test for the C.A.R.L. three-round limiter, primarily with AR-15 platforms and their variants. The presenter, exhibiting expert-level knowledge, details how the limiter's functionality is dependent on proper hammer reset and cam rotation, often requiring specific trigger group components like a milspec trigger. Crucially, the video provides a detailed modification guide for the 'third sear' to ensure correct engagement with the cam, addressing issues that lead to more than a three-round burst. It also explores compatibility with various platforms including AR-9s, .300 Blackout, and .22LR AR-15s, highlighting the importance of back pressure from suppressors and clean firearm operation.

Quick Summary

The C.A.R.L. three-round limiter is compatible with AR-15 platforms and various Super Safety kits like Atreus, Hoffman Tactical, and Arcfire, ideally with a milspec trigger. Proper function relies on sufficient hammer reset and back pressure, often from a suppressor. Issues with more than a three-round burst can be resolved by modifying the third sear to ensure correct cam engagement.

Chapters

  1. 00:02Introduction: C.A.R.L. Limiter Test
  2. 00:26Channel Sponsors & Disclaimer
  3. 00:40Compatibility: AR-15, .300 BLK, AR-9 Issues
  4. 01:08Milspec Triggers & CZ EVO Mags
  5. 01:36Hammer & Cam Rotation Mechanics
  6. 01:55Fixing Cam Rotation: Third Sear Mod
  7. 02:21Role of Back Pressure & Suppressors
  8. 02:45Testing on Kel-Tec ST-50
  9. 03:40ST-50 vs. Original Design Warning
  10. 04:01Discount Code: PLEASE
  11. 04:1122LR AR-15 Compatibility Test
  12. 05:1322LR AR-15 Functionality Results
  13. 06:059mm PCCs (AR9s) Challenges
  14. 07:01Conclusion & Future Products

Frequently Asked Questions

What is the C.A.R.L. three-round limiter and what firearms is it compatible with?

The C.A.R.L. is a three-round limiter designed for firearms like the AR-15 platform. It works with various Super Safety kits, including Atreus, Hoffman Tactical, and Arcfire, and generally requires a milspec trigger. Compatibility with AR-9s and .22LR AR-15s can be more complex and may require specific modifications or clean operation.

How can I fix the C.A.R.L. limiter if it's allowing more than a three-round burst?

If the C.A.R.L. limiter is not functioning correctly, the issue often lies with the 'third sear' not properly engaging the cam. You can fix this by either bending the third sear outward slightly if it's touching the hammer, or by trimming the sear if it's too thick, ensuring it interfaces correctly with the cam.

Does the C.A.R.L. limiter work with 9mm AR-9 platforms?

Compatibility with 9mm PCCs (AR-9s) is challenging. The C.A.R.L. can work if the AR-9 can be successfully 'super safetied,' but factors like buffer type can affect performance. Generally, 'super safing' an AR-9 is considered difficult, impacting C.A.R.L. functionality.

What role does a suppressor play in the C.A.R.L. limiter's operation?

High back pressure, often generated by a suppressor, is crucial for the C.A.R.L. limiter's correct function. The back pressure helps kick the hammer back with enough force to rotate the cam, which is necessary for the limiter to engage the sear and restrict fire to three rounds.

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