FN M249 Trigger Mechanism


This trigger mechanism includes:

  • Safety
  • Sear
  • Sear Pin
  • Trigger Mechanism Retaining Spring
  • Pistol Grip
  • Trigger Guard
  • Trigger Assembly
  • Trigger Pin
  • Trigger Spring
  • Trigger Module Pin
  • Front Trigger Guard Pin

Manufacturer: FN America


  • Brand: FN America
  • Caliber: .223 Rem,5.56x45mm
  • Finish / Color: Black
  • Firearm Type: Rifle
  • Material: Polymer,Aluminum,Steel
  • Models Fit: FN M249 SAW,FN M249S,FN MINIMI

Unlocking the Potential: A Comprehensive Guide to the M249 Binary Trigger

The M249 Binary Trigger is a groundbreaking enhancement in the realm of firearms, particularly for enthusiasts looking to elevate their shooting experience. This trigger system uniquely bridges the gap between semi-automatic and full-automatic firing capabilities without altering the fundamental classification of the firearm. In this extensive guide, we will delve into every aspect of the M249 Binary Trigger, from its intricate design to its legal implications, installation, and real-world applications.

Introduction to the M249 Binary Trigger

The M249 Binary Trigger is designed to offer a rapid fire capability by allowing a shot on both the pull and release of the trigger. This innovative mechanism not only increases the firing rate but does so within the legal confines of a semi-automatic firearm system. Understanding how this trigger works and its unique benefits can drastically enhance your shooting effectiveness and enjoyment.

Design and Mechanics of the M249 Binary Trigger

The M249 Binary Trigger incorporates a complex yet robust design that enables it to function in a dual-mode capacity. Here’s how it works:

  1. Trigger Pull: Initiates the firing of one round, similar to traditional semi-automatic weapons.
  2. Trigger Release: Automatically fires a second round, a feature not found in standard semi-auto triggers.

This dual-action mechanism is achieved through a series of internal modifications that do not alter the external appearance of the firearm but significantly enhance its functionality. The design typically involves modifications to the trigger hammer, disconnector, and the trigger itself, ensuring that each pull and release is smooth and also consistent.

For a visual explanation of the trigger mechanism, Midwest Gun Works offers a detailed schematic.

Advantages of Using the M249 Binary Trigger

The primary advantages of integrating an M249 Binary Trigger into your firearm include:

  • Enhanced Firing Rate: Nearly doubles the rate of fire, providing a pseudo-full-auto experience without the legal restrictions.
  • Versatility: Offers the ability to switch between standard semi-automatic and binary firing modes, adapting to various shooting conditions and needs.
  • Legal Compliance: Maintains the firearm’s classification as a semi-automatic, making it a favorable option in regions where full-automatic weapons are banned.

Binary triggers, including the M249 Binary Trigger, generally remain legal under federal law in the United States as they do not convert the firearm into a fully automatic weapon. However, state laws vary significantly. For instance, states like California and New York have stricter regulations that may classify binary triggers under prohibited items. It’s crucial to consult ATF regulations and local laws before purchasing and installing a binary trigger.

Installation Process of the M249 Binary Trigger

Installing the M249 Binary Trigger requires precision and an understanding of your firearm’s mechanics. Here’s a basic outline of the installation process:

  1. Ensure the firearm is unloaded: Safety first.
  2. Remove the existing trigger assembly: Follow your firearm’s manual to remove the current trigger system.
  3. Install the binary trigger: Using the provided instructions from the manufacturer, such as those found on Rare Breed Trigger Co., replace the old trigger with the new binary trigger.
  4. Safety Check: Ensure everything is properly aligned and functional before reassembling the firearm.

Compatibility and Performance

The compatibility of the M249 Binary Trigger varies depending on the firearm model. It is specifically designed for models like the M249 or similar platforms. Performance tests generally show a significant improvement in firing rate and a modest enhancement in accuracy due to the reduced interval between shots.

For specific compatibility details, refer to resources like Ordnance Defence.

User Reviews and Feedback

Feedback from users who have installed the M249 Binary Trigger tends to be overwhelmingly positive, citing improved firing rates and an enhanced shooting experience. However, some users note the need for practice to get accustomed to the binary firing mode, as it can initially be challenging to manage the rapid rate of fire.

Pricing and Availability

The cost of the M249 Binary Trigger can vary based on the manufacturer and also quality. Typically, prices range from $350 to $500. For purchasing options, check out platforms like Rare Breed Trigger Co. which offer a variety of binary triggers.


The M249 Binary Trigger is a significant innovation in firearm technology, offering shooters the ability to enhance their firing rate within legal bounds. Whether for tactical applications, sport shooting, or personal defense, this trigger modification provides an exciting, yet responsible, enhancement to your firearm’s capabilities. As with any modification, understanding the legal, safety, and performance implications is crucial.


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