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

If you own an HK MR223 or MR556 and have been hunting for a trigger that genuinely changes how the rifle feels under recoil, the FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger from Rare Breed is worth a hard look. This is not a gimmick. It is a mechanical forced-reset system that re-engages the sear during the return stroke, letting you stay on target with a rhythm that feels both fast and controlled. We have run this trigger in several MR-platform rifles, and the flat face gives a consistent finger placement that helps with that reset timing. It is a purpose-built component for these specific HK models, not a generic drop-in that needs filing or fitting.

Overview

The FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger is designed exclusively for the HK MR223 and MR556 platforms. Rare Breed engineered this unit with a three-position selector that includes safe, semi-automatic, and the forced-reset function. Unlike binary triggers that fire on the pull and release, this system uses the bolt carrier’s forward motion to mechanically reset the trigger, meaning you have to let the trigger move forward with the bolt before it can break again. That distinction matters because it keeps the trigger finger in the same firing cycle as the action, reducing the tendency to slap or jerk the trigger under speed. The flat bow is milled from billet aluminum and anodized to match the factory HK finish, so it does not look out of place in a precision rifle.

Features & Specs

This trigger is single-stage with a crisp break that sits around 4.5 to 5 pounds out of the box. The forced-reset function is adjustable via a set screw that tunes the over-travel, letting you dial in how much follow-through you want before the trigger resets. Here are the key specs and features:

• Manufacturer: Rare Breed. Category: Triggers. Specifically designed for HK MR223 and MR556 lower receivers with standard mil-spec trigger pocket dimensions.
• Three-position selector: Safe, Semi, and Forced Reset. The forced-reset position is clearly marked and requires deliberate selector movement to engage.
• Flat trigger bow with a textured face reduces finger slip during rapid strings. Installs with standard trigger pins and does not require permanent modification to the receiver.

We have found that the flat shoe is particularly helpful for shooters who run a high grip or have longer fingers, as it keeps the pad of the finger centered on the trigger face. The reset is audible and tactile, which is useful when you are working on timer drills or shooting from unconventional positions.

Who It’s For

This trigger is for the HK owner who wants a legitimate mechanical edge in fast-paced shooting without swapping to a lower receiver or running a drop-in cassette that may not fit the MR-platform correctly. If you compete in two-gun or three-gun matches that allow forced-reset triggers, this is a direct upgrade that leverages the MR556’s reliable gas system. It is also appropriate for serious enthusiasts who train for defensive scenarios and want a trigger that forces disciplined finger movement. The FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger is not a toy; it is a training tool that rewards proper trigger control and penalizes poor technique. If you have experience with other forced-reset designs, you will notice that Rare Breed’s implementation on the HK platform has less over-travel slop and a more defined wall.

• Ideal for competitive shooters running HK MR223 or MR556 rifles in USPSA, 3-Gun, or outlaw matches where forced-reset triggers are permitted by division rules.
• Suited for advanced enthusiasts who want to practice recoil management and trigger reset discipline without switching to a different firearm platform.
• Recommended for gunsmiths or armorers who are comfortable with trigger installs and understand the mechanical function of forced-reset systems.

Shipping & FFL

This trigger is classified as a firearm component and ships directly to your door. No Federal Firearms License (FFL) transfer is required for purchase or delivery within the United States. However, local state and municipal laws regarding forced-reset triggers vary significantly. It is your responsibility to verify that this product is legal to own and use in your jurisdiction before placing an order. We do not accept returns on installed triggers, and we do not offer refunds for orders that are refused by a shipping carrier due to local restrictions. If you have any questions about compatibility or installation, give us a call or send an email before you buy. We are happy to walk through the fitment process and answer any technical questions about the FRT-MR3 (Flat) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & MR556.

• No FFL transfer required for shipment to residential addresses within the United States.
• Buyer assumes full responsibility for compliance with all local, state, and federal laws regarding forced-reset triggers.
• Installation should be performed by a qualified armorer. Do not attempt to modify the trigger or use it in non-HK platforms.