Founded in 2008 by passionate firearm enthusiasts, Primary Weapons Systems began by manufacturing high-performance muzzle devices. Extensive testing on a variety of rifles, from M4s to AK-47s, revealed a significant difference in maintenance requirements after high round counts. This discovery led to the development of the PWS long-stroke piston system, which preserves the core attributes of the AR-15 platform while reducing the need for maintenance in high-volume shooting and adverse conditions. The PWS MK1 MOD 2-M Multi-Caliber Lower is crafted from T6 7075 forged aluminum and features a hard coat black anodized finish per MIL-A-8625F Type III Class 2. Designed for AR-15 compatibility, it includes proprietary components such as a left-side magazine release, bolt catch spring, bolt catch screws, tension screw, bolt release lever and bolt release through pin, delivering enhanced functionality and reliability.

Features an ambidextrous magazine release for easy operation from either side
Features an ambidextrous bolt catch for convenient operation from either side
A lightweight design ensures effortless carry and improved agility in the field
The integrated trigger guard enhances durability and provides a seamless, ergonomic design

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If you live in California, please read this notice before ordering.

Shipping Restrictions

It is the customer’s responsibility for understanding state laws regarding all purchases made. For a comprehensive list of all Shipping Restrictions, please refer to our Shipping Restrictions By State Page found Here.

All NFA Rules Apply

These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Magazines will be removed from firearms when shipping to states with magazine capacity restrictions.

Must be 21 or older to purchase.

WARNING: Handling firearms or firearms parts can expose you to lead and other petroleum products known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands thoroughly after handling. For more information go to www.p65warnings.ca.gov (CA Health and Safety Code Section 25249.6).

Primary Weapons Systems MK1 Mod 2-M Stripped Lower 5.56x45mm, Black