FRT-MR3

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

FRT-MR3™ Overview for HK MR223 and HK MR556 Platforms

The FRT-MR3™ is a three-position forced reset trigger system designed for use with HK MR223 and HK MR556 rifles. Manufactured and assembled in the United States, the trigger assembly includes a three-position ambidextrous safety selector and anti-walk pins intended to support installation and component retention.

Operating Characteristics

The FRT-MR3™ utilizes a forced reset mechanism that mechanically resets the trigger during the firearm’s operating cycle after each shot. The design requires a separate trigger pull for every round fired. The selector offers three positions: Safe, Semi, and FRT.

Design Features

Three-Position Selector

The system incorporates an ambidextrous selector with Safe, Semi, and Forced Reset settings. The control layout is intended to be accessible to both left- and right-handed users.

Installation Components

The trigger package includes anti-walk pins and related hardware designed for installation in compatible lower receivers. These components help maintain trigger pin alignment during operation.

Construction Materials

The FRT-MR3™ is manufactured using materials that may include 7075 anodized aluminum along with heat-treated steel components such as 4140 and S7 steel. These materials are commonly used in firearm components due to their durability and resistance to wear.

Compatibility

The FRT-MR3™ is engineered for use with HK MR223 and HK MR556 rifles that retain the factory semi-automatic bolt carrier group (BCG). The manufacturer specifies compatibility with original factory-supplied semi-automatic BCG configurations and recommends maintaining the factory buffer and recoil spring setup.

According to the stated specifications, the trigger is not designed for use with HK416 or BRN4 full-automatic bolt carrier groups.

Trigger Function

The forced reset mechanism returns the trigger to its reset position during the cycling process and prevents another trigger pull until the bolt carrier group returns to battery. The shooter must initiate a new trigger pull for each shot fired.

Summary

The FRT-MR3™ is a specialized trigger system intended for HK MR223 and HK MR556 platforms. Its primary characteristics include a three-position selector, forced reset operating mechanism, included installation hardware, and compatibility requirements centered on factory semi-automatic operating components.