Quick Tip: Installing the Stern Defense 5.56 to 9mm AR-15 Magwell Adapter

Published on April 30, 2019
Duration: 1:46

This guide provides expert instructions from Brownells on installing the Stern Defense 5.56mm to 9mm AR-15 Magwell Adapter. The process involves securing the adapter with a tensioning screw and nylon-tipped set screws to ensure a wobble-free fit, which is critical for reliable feeding of Glock 9mm magazines. The adapter also features an arm that activates the bolt stop on the last round.

Quick Summary

The Stern Defense 5.56 to 9mm AR-15 Magwell Adapter installs easily into your AR-15 lower receiver. Secure it with the tensioning screw and nylon-tipped set screws for a wobble-free fit, ensuring reliable feeding of Glock 9mm magazines. It also activates the last-round bolt hold-open feature.

Chapters

  1. 00:05Introduction to AR-15 9mm Conversion
  2. 00:10Introducing the Stern Defense Adapter
  3. 00:16Initial Adapter Placement
  4. 00:25Securing the Tensioning Screw
  5. 00:43Tightening Set Screws
  6. 01:00Preventing Magazine Wobble
  7. 01:14Testing with Glock Magazine
  8. 01:24Bolt Stop Operation
  9. 01:35Conclusion

Frequently Asked Questions

How do you install the Stern Defense 5.56 to 9mm AR-15 Magwell Adapter?

Insert the adapter into the AR-15 magazine well, depress the mag catch until it clicks, then tighten the tensioning screw and the two nylon-tipped set screws to ensure a snug, wobble-free fit for reliable feeding.

What is the purpose of the tensioning screw and set screws on the Stern Defense magwell adapter?

These screws are crucial for eliminating any play or wobble in the adapter. A secure fit prevents the inserted magazine from moving, which is essential for consistent and reliable feeding of 9mm ammunition into the AR-15.

Does the Stern Defense AR-15 magwell adapter support last-round bolt hold-open?

Yes, the adapter features a small arm designed to engage the AR-15's bolt stop mechanism. This ensures that the bolt will lock open after the last round is fired from a 9mm Glock magazine.

What types of magazines can be used with the Stern Defense 5.56 to 9mm AR-15 Magwell Adapter?

This adapter is specifically designed to allow an AR-15 lower receiver to accept 9mm magazines manufactured by Glock. It facilitates a conversion from the standard 5.56mm platform.

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