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

Designed for precision-oriented shooters who require enhanced rate-of-fire control without compromising safety or mechanical reliability, the FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 represents a significant advancement in trigger system engineering. Manufactured by Rare Breed, this drop-in assembly capitalizes on the forced-reset principle to deliver consistent, repeatable trigger resets across three distinct selector positions. The flat trigger profile reduces finger travel and provides a more consistent pull axis, making this unit a preferred upgrade for those operating HK-pattern rifles in competitive, training, or duty environments.

Overview

The FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 redefines the interface between shooter and firearm. Unlike conventional single-stage triggers that require a full manual reset after each shot, this system mechanically forces the trigger forward immediately following the hammer release, enabling a faster follow-up cycle. The three-position safety selector offers safe, semi-automatic, and forced-reset modes, each clearly indexed for unambiguous selection. The flat trigger shoe is machined from billet aluminum with a hard-coat anodized finish, reducing friction and providing a tactile, consistent surface under gloved or bare-hand conditions. This trigger is purpose-built for the HK MR223 and MR556 platforms, requiring no permanent modifications to the lower receiver.

Features & Specs

Mechanically, the FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 integrates a spring-loaded reset cam that engages the trigger bar upon hammer fall, forcing the trigger forward to the reset point. This eliminates the need for the shooter to fully release the trigger between shots, reducing lock time and enabling a more fluid shooting cadence. The trigger pull weight is set at a crisp 4.5 to 5.0 pounds, with minimal overtravel and a positive break. Below are the key specifications and included components:

• Single-stage design with forced-reset functionality across three selectable positions: Safe (S), Semi-Automatic (1), and Forced Reset (3).
• Flat trigger shoe constructed from 7075-T6 billet aluminum with Type III hard-coat anodizing; black finish for reduced glare and corrosion resistance.
• Drop-in installation for HK MR223 and HK MR556 lower receivers; includes trigger, hammer, disconnector, selector, springs, and pins.
• Pull weight: 4.5-5.0 lbs measured at the center of the shoe; single-stage break with tactile reset.
• Overall trigger travel: 0.120 inches; reset travel: 0.030 inches (forced reset cycle).
• Operating temperature range: -20°F to 160°F; tested for 10,000+ cycles with no degradation in reset timing.

Who It’s For

This trigger system addresses the specific needs of shooters who demand mechanical precision and repeatable performance under high-volume fire. The FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is intended for experienced firearms owners who understand the operational characteristics of forced-reset mechanisms and who require a reliable upgrade for their HK-pattern rifles. It is well-suited for three-gun competitors, law enforcement armorers evaluating advanced trigger systems, and civilian shooters who train for rapid target transitions. The flat trigger profile benefits shooters with shorter fingers or those who prefer a more perpendicular finger placement relative to the bore axis. Users should have a working knowledge of trigger group installation and function testing prior to fitting this component.

Shipping & FFL

This item is classified as a firearm component and will ship directly to your provided address. No Federal Firearms License (FFL) transfer is required for this trigger assembly as it does not constitute a firearm frame or receiver under ATF guidelines. However, it is the sole responsibility of the purchaser to verify that the installation and use of this product complies with all applicable federal, state, and local laws. Rare Breed Triggers and the retailer assume no liability for improper installation or misuse. Standard shipping rates apply, and delivery is typically within 5-7 business days of order processing. Signature may be required upon delivery.