FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556

The FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 represents a precision-engineered upgrade for shooters operating within the HK MR-platform ecosystem. Manufactured by Rare Breed, this trigger system is designed to integrate with the specific bolt carrier group geometry and receiver dimensions of the HK MR223 and MR556 rifles. Unlike standard drop-in triggers, the FRT-MR3 utilizes a mechanical forced-reset mechanism that re-engages the sear as the bolt carrier cycles, enabling a controlled, high-speed shooting cadence without modification to the host firearm’s internal safety block or fire control group pocket. This third-position trigger offers the user three distinct selector positions: Safe, Semi-Automatic, and a dedicated forced-reset mode.

Overview

The FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is purpose-built for shooters who require a repeatable, consistent trigger pull under dynamic firing conditions. Rare Breed has engineered this unit to meet the interface specifications of the HK MR223 and MR556 lower receivers, ensuring compatibility with the factory trigger housing pins and hammer spring orientation. The flat trigger shoe provides a consistent finger placement surface, reducing pull weight variation caused by finger placement shifts. The forced-reset mechanism is a single-stage design, meaning there is no perceptible take-up or creep; the shooter experiences a crisp break followed by an immediate reset that is mechanically driven by the bolt carrier’s forward momentum. This design philosophy prioritizes shot-to-shot consistency and shooter control over raw cyclic rate.

Features & Specs

• Three-position selector configuration: Safe (blocked), Semi-Automatic (standard single-shot per trigger pull), and Forced-Reset Mode (mechanically re-engages sear after each shot, allowing trigger pull to reset without manual release).
• Flat-profile trigger shoe with a serrated face, designed to reduce over-travel and provide a consistent trigger finger index point across varied grip angles.
• Manufactured from heat-treated steel with a phosphate finish, rated for continuous use with 5.56x45mm NATO pressure levels in the MR223 and MR556 platforms.
• Single-stage pull weight calibrated to a factory specification of 4.5 to 5.5 pounds as measured at the center of the shoe, with no take-up or over-travel adjustment required.
• Includes all necessary drop-in components: trigger shoe, hammer, disconnector, selector lever, spring set, and retention pins. No permanent modification to the receiver is required for installation.

Who It’s For

This trigger is intended for experienced HK MR223 and MR556 owners who understand the mechanical operation of forced-reset trigger systems and the legal requirements surrounding their installation. It is suitable for competitive shooters who train in controlled pairs, rapid target transitions, or time-constrained stages where a consistent reset point reduces split times. Law enforcement armorers and civilian marksmen who have completed formal training on forced-reset trigger operation will find the flat shoe geometry advantageous for maintaining a high grip position without trigger finger interference. The FRT-MR3 is not recommended for new shooters or those unfamiliar with the reset characteristics of forced-reset mechanisms, as the trigger’s audible and tactile feedback differs significantly from standard AR-pattern single-stage triggers.

Shipping & FFL

This FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is classified as a firearm component and does not require transfer through a Federal Firearms License (FFL) dealer when shipped to a residential address within the United States. However, state and local laws regarding trigger mechanisms vary. It is the purchaser’s sole responsibility to verify that possession and use of a forced-reset trigger is legal in their jurisdiction prior to ordering. Rare Breed and this retailer do not assume liability for compliance with state, county, or municipal regulations. All shipments are processed via UPS Ground or FedEx Home Delivery with adult signature required. International shipping is not available. Please allow 5 to 10 business days for order processing and fulfillment. By purchasing this product, you confirm that you are at least 18 years of age and that you are not prohibited from owning firearm components under federal law.