KE Arms KP9 Polymer Lower 9mm Receiver

Published on April 4, 2022
Duration: 13:15

This video provides an in-depth look at the KE Arms KP-9, a 9mm polymer lower receiver. Featuring insights from Ian McCollum and Russell Phagan, it details the design, compatibility, and unique technical aspects of the KP-9, including its Glock magazine integration, adjustable ejector, and blowback bolt mechanics. The discussion highlights practical considerations for builders and shooters looking to assemble a 9mm AR-15 platform.

Quick Summary

The KE Arms KP-9 is a 9mm polymer lower receiver designed for Glock magazines, building on the KP-15 platform. It features an ambidextrous magazine release, an adjustable 'shark fin' ejector, and requires specific bolt carrier machining for Glock magazine feed lips. A minimum 5.4oz buffer is recommended for reliable blowback operation.

Chapters

  1. 00:00Introduction to KE Arms KP-9
  2. 00:38Design and Development
  3. 01:19Glock Magazine Choice
  4. 02:08Upper and Bolt Compatibility
  5. 03:07Adjustable Ejector and Mag Stop
  6. 04:459mm Blowback Bolt Mechanics
  7. 06:24Barrel and Feeding Reliability
  8. 08:23Live Fire Demonstration
  9. 10:24Compatibility and Tuning
  10. 11:59LRBHO and Availability

Frequently Asked Questions

What is the KE Arms KP-9?

The KE Arms KP-9 is a 9mm polymer lower receiver designed as a 9mm counterpart to the KP-15. It specifically accommodates Glock-pattern magazines and incorporates features necessary for reliable blowback operation in a polymer platform.

What magazines does the KE Arms KP-9 use?

The KE Arms KP-9 is designed to use readily available and affordable Glock-pattern 9mm magazines. This choice allows for easier integration into the standard AR-15 lower receiver dimensions without requiring proprietary upper receivers.

What are the key technical features of the KE Arms KP-9?

Key features include a grafted 9mm magwell, structural reinforcements for polymer construction, an ambidextrous magazine release, and a unique adjustable 'shark fin' ejector that also acts as a magazine over-travel stop.

What buffer weight is recommended for the KE Arms KP-9?

For 9mm blowback operation with the KE Arms KP-9, a minimum buffer weight of 5.4oz is recommended. Heavier buffers, such as 8oz, can be used to further reduce muzzle jump, especially with hotter ammunition loads.

Related News

All News →

More Tactical & Gear Videos You Might Like

More from Forgotten Weapons

View all →