CMMG .22 Conversion with a PISTON AR

Published on November 19, 2024
Duration: 2:36

This video demonstrates how to install a CMMG .22 conversion kit into a piston-driven AR-15 upper receiver. It highlights the design differences, specifically the rebated area on the .22 bolt, which allows it to function with piston systems by clearing the piston rod. The presenter notes that compatibility can vary depending on the specific piston system, with some like PWS having integrated pistons in the BCG requiring a different approach.

Quick Summary

CMMG .22 conversion kits are designed with a rebated area on the bolt to clear the piston rod in piston-driven AR-15s. While compatible with systems like Adams Arms, those with integrated pistons in the BCG, like PWS, require piston removal. Always ensure your firearm is unloaded before installation.

Chapters

  1. 00:03Introduction to .22 Conversion Kits in Piston ARs
  2. 00:13Compatibility Considerations for Piston ARs
  3. 00:21Demonstrating on an Old School CMMG Piston Upper
  4. 00:34Piston Upper Mechanics vs. .22 Kit
  5. 00:43PWS Piston System Differences
  6. 00:53Breaking Open the AR-15 and BCG Comparison
  7. 01:06Piston Contact Ledge on BCG
  8. 01:13Rebated Area on .22 Conversion Kit Bolt
  9. 01:30Piston Clearance and Interference
  10. 01:33Compatibility with Adams Arms and PWS
  11. 01:41PWS BCG with Integrated Piston
  12. 01:58Installing the .22 Conversion Kit
  13. 02:03Loading and Inserting the .22 Magazine
  14. 02:14Testing Functionality with Piston Still In
  15. 02:20Conclusion and Q&A Invitation

Frequently Asked Questions

Can I use a CMMG .22 conversion kit in any piston AR?

Not necessarily. Compatibility depends on the specific piston system. Systems like Adams Arms are generally compatible due to similar mechanics. However, piston systems with the piston integrated into the bolt carrier group, such as PWS, require the piston to be removed before installing the .22 kit.

What is the key design feature that allows .22 conversion kits to work with piston ARs?

The CMMG .22 conversion kit bolt features a specific rebated area on its top surface. This design allows the piston rod from the upper receiver to pass over and clear the bolt without causing interference or malfunctions.

How does the CMMG .22 conversion kit bolt differ from a standard AR-15 bolt carrier group?

A standard AR-15 bolt carrier group typically has a solid ledge on top where the piston makes contact. The CMMG .22 conversion kit bolt has a recessed or rebated section in this area, specifically engineered to allow the piston rod to clear it.

What tools are needed to install a CMMG .22 conversion kit in a piston AR?

While specific tools for the .22 kit installation are minimal, you'll need standard AR-15 disassembly tools to remove the original bolt carrier group. The video also mentions the McFadden Lightning Loader for efficiently loading the .22 magazines.

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