Smyth Busters: Can an AR-15 Fire Full Auto With an M16 Carrier?

Published on July 29, 2020
Duration: 3:15

This video debunks the myth that installing an M16 bolt carrier group (BCG) into an AR-15 automatically makes it fire full-auto. It clarifies that a full-auto conversion requires specific lower receiver components like a full-auto trigger group and an auto sear, which are absent in a standard AR-15. The M16 BCG's extra lug is designed solely to interact with the auto sear.

Quick Summary

Installing an M16 bolt carrier group (BCG) into an AR-15 does not make it fire full-auto. The M16 BCG has an extra rear lug designed to engage an auto sear, a component typically absent in standard AR-15 lower receivers. A full conversion requires specific trigger groups and lower receiver modifications.

Chapters

  1. 00:00Intro: The M16 BCG Myth
  2. 00:33BCG Comparison: Semi vs. Full Auto
  3. 01:08Full Auto Conversion Requirements
  4. 01:49Semi-Auto Conversion Kits Explained
  5. 02:36Myth Busted & Legal Disclaimer

Frequently Asked Questions

Will installing an M16 bolt carrier group into my AR-15 make it fire full-auto?

No, installing an M16 bolt carrier group (BCG) alone will not make an AR-15 fire full-auto. The M16 BCG has an extra lug designed to interact with an auto sear, which is absent in a standard AR-15 lower receiver and trigger group.

What parts are needed to convert an AR-15 to full-auto?

A full-auto conversion requires more than just an M16 bolt carrier group. You also need a compatible lower receiver with the correct wall thickness, a full-auto trigger group, and an auto sear specifically designed for automatic fire.

What is the difference between an AR-15 BCG and an M16 BCG?

The primary difference is the M16 bolt carrier group has an extended rear lug, often called a 'trip' or 'key', designed to engage the auto sear for automatic fire. AR-15 BCGs lack this extended lug to prevent full-auto function.

Are semi-auto conversion kits for M16s legal?

Yes, semi-auto conversion kits are used to make surplus M16s legally fire only in semi-automatic mode. These kits replace NFA-regulated parts, ensuring compliance for standard civilian or law enforcement use.

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