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

Overview

The FRT-MR3™ Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is a precision-engineered drop-in trigger system designed exclusively for the HK MR223 and HK MR556 platform. Manufactured by Rare Breed, this trigger represents a specialized adaptation of forced reset technology, tailored to the unique bolt carrier group geometry and receiver dimensions of these specific HK-model rifles. Unlike standard triggers, the FRT-MR3™ utilizes a mechanical forced reset mechanism that returns the trigger shoe forward immediately following a shot cycle, enabling a distinct three-position selector configuration: Safe, Semi-Automatic, and the forced reset position. Each unit is assembled from heat-treated, mil-spec steel components and undergoes individual function testing to ensure consistent performance across the full operating range of the MR223 and MR556.

Features & Specs

The FRT-MR3™ Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 incorporates a single-stage trigger pull with a defined break point, avoiding the mushiness common in aftermarket HK triggers. The hammer spring is calibrated to deliver reliable primer strikes on both 5.56 NATO and .223 Remington ammunition while maintaining the forced reset timing window. All internal surfaces are precision-ground with a phosphate finish for corrosion resistance and reduced friction over extended use.

• Three-position selector: Safe, Semi-Automatic, and Forced Reset (3-position marked selector included)
• Single-stage trigger pull with approximately 4.5-5.5 lb break weight (measured per Rare Breed QC standards)
• Drop-in installation using factory HK MR223/MR556 trigger pin holes; no receiver modification required

• Heat-treated 8620 steel hammer and trigger components with manganese phosphate finish
• Includes proprietary Rare Breed hammer spring and trigger return spring matched to MR223/MR556 bolt carrier weights
• Each unit ships with a test-fire verification card from Rare Breed

• Designed for semi-automatic receivers only; not compatible with full-auto sear packs or registered lightning links
• Ambidextrous safety selector compatibility maintained with standard HK MR223/MR556 lower receivers
• Overall trigger component weight: 4.2 ounces (complete assembly, including selector)

Who It’s For

This FRT-MR3™ Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is intended for experienced HK platform owners who require a mechanical trigger system that operates within the bounds of semi-automatic firearm design while offering a distinct cycling characteristic. It is suited for shooters who understand the maintenance requirements of forced reset mechanisms, including proper lubrication intervals and bolt carrier group timing checks. The trigger is not recommended for novice shooters, competition divisions that prohibit forced reset triggers, or any configuration involving binary trigger classifications. Users should verify that their specific MR223 or MR556 lower receiver is within factory headspace and pin hole location tolerances before installation.

Shipping & FFL

This product ships directly to your door within the contiguous United States. No Federal Firearms License (FFL) transfer is required for this item because the FRT-MR3™ is classified by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) as a firearm component part, not a firearm receiver or frame. However, it is your sole responsibility to confirm that ownership and installation of this forced reset trigger complies with all applicable federal, state, and local laws, regulations, and ordinances. Rare Breed and this retailer assume no liability for purchaser non-compliance. Some states and municipalities have enacted specific restrictions on forced reset triggers; check your jurisdiction before ordering. By purchasing this FRT-MR3™ Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556, you certify that you are legally eligible to own and install firearm components and that you are not a prohibited person under federal law. Shipping is via UPS Ground with adult signature required. Estimated transit time is 3-7 business days after order processing.