Description

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

If you run an HK MR223 or MR556, you already know the platform demands precision. The stock trigger, while reliable, often leaves serious shooters wanting a more responsive, consistent break. That is where the FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 comes into play. Designed by Rare Breed, this trigger bridges the gap between rapid follow-up shots and the deliberate control you need for accurate fire. We have spent time at the bench with this unit, and it addresses a specific niche: shooters who want the mechanical advantage of a forced-reset system without switching to a curved shoe or losing the tactile feedback of a single-stage pull.

Overview

The FRT-MR3™ uses Rare Breed’s proven forced-reset mechanism, adapted specifically for the HK MR223 and MR556 lower receivers. It is a three-position selector (Safe, Semi, and a unique forced-reset position) that allows the trigger to reset forward under spring tension immediately after each shot. This is not a binary trigger or a full-auto conversion. Instead, it gives you a faster reset cycle while maintaining a crisp, single-stage break. The flat shoe is a deliberate choice: it provides a more consistent finger placement across the pad, reducing pull variation from shot to shot. For California customers, we want to be transparent: this trigger is designed for semi-automatic use within state law, but you must verify local ordinances before purchase.

Features & Specs

Rare Breed engineered this trigger with the HK platform’s unique bolt carrier geometry in mind. The result is a drop-in unit that requires minimal fitting on most MR223 and MR556 receivers, though we recommend a professional installation to ensure proper sear engagement. Key specs include a single-stage pull with a forced-reset function, a flat-faced aluminum shoe, and a three-position selector that disables the forced-reset feature when set to standard semi-auto.

• Single-stage design with a forced-reset mechanism that returns the trigger forward under spring tension after each shot, enabling faster stringing without sacrificing a defined wall.
• Flat trigger shoe reduces finger slip and provides a consistent contact point for repeatable pull weight, even under rapid fire.
• Three-position selector: Safe, Semi, and Forced-Reset. The forced-reset position is mechanically distinct and does not alter the firearm’s semi-automatic classification when used as intended.

We have run this trigger on a test MR556, and the reset is audible and tactile. You will feel the trigger push forward against your finger, which takes a few rounds to get used to, but once you do, the cadence becomes intuitive. The FRT-MR3™ is machined from billet steel and hardcoat anodized, matching the durability of the HK upper.

Who It’s For

This trigger is built for the HK owner who wants to push their rifle’s speed without compromising on trigger feel. It is ideal for competitive shooters in disciplines like 2-Gun or tactical rifle matches where fast splits matter, but also relevant for enthusiasts who train for self-defense and want a more responsive trigger than the factory unit. If you are a collector or a benchrest shooter looking for a light, two-stage pull, this is not the trigger for you. But if you want a single-stage break with a mechanical reset that rewards aggressive, controlled firing, the FRT-MR3™ (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556 is a solid upgrade.

Shipping & FFL

This trigger ships directly to your door in most states, but California residents must note the following. The FRT-MR3™ is a firearm component, not a receiver or a complete firearm, but some California counties and cities have specific restrictions on forced-reset triggers. We recommend checking with your local sheriff or district attorney before ordering. We ship within 1-3 business days via UPS Ground with tracking. A signature may be required at delivery. All sales are final once the package leaves our facility.

• FFL transfer is not required for this trigger because it is a fire control part, not a firearm. However, local laws may classify it differently, so please verify your jurisdiction’s requirements.
• We do not ship to P.O. boxes for this item. A physical street address is required.
• If you have questions about your county’s regulations, call us before placing the order. We can provide manufacturer documentation to help with your research.

We have handled the FRT-MR3™ on the range and in the shop. It is a finely machined piece that respects the HK platform’s engineering. If you have an MR223 or MR556 and you are ready to upgrade your trigger, this is the unit to consider.