FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K

The FRT-RD3™ (SEF) represents a significant advancement in trigger technology for roller-delayed blowback platforms. Engineered by Rare Breed specifically for the HK MP5, MP5K, SP5, and SP5K, this two-stage, 3-position forced reset trigger (FRT) system delivers a distinct mechanical cycling experience. Designed around the Single-Edge Fire (SEF) lower configuration, this trigger unit integrates forced-reset functionality into a classic HK platform without permanent modification to the host firearm.

Overview

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is a drop-in trigger pack that replaces the factory SEF trigger group. It utilizes a patented forced-reset mechanism that physically returns the trigger forward after each shot, requiring the shooter to release and re-engage the trigger for each subsequent discharge. The two-stage design provides a distinct take-up and wall before the forced-reset cycle initiates, offering precise control over the firing sequence. This unit is compatible with both full-size and K-model MP5 variants, including semi-automatic SP5 and SP5K models, when installed in a registered SEF lower receiver or compatible housing.

Features & Specs

• Mechanical forced-reset operation: Trigger is physically reset forward after each shot, independent of the shooter’s finger position, enabling a repeatable, two-stage trigger pull cycle.
• Three-position selector compatibility: Functions with standard SEF (0-1-2) selectors for safe, semi-automatic, and the unique forced-reset firing mode. The third position activates the forced-reset cycling sequence.
• Two-stage trigger pull: First stage provides approximately 2.5-3.0 pounds of take-up; second stage breaks at a consistent 4.5-5.5 pounds, with a crisp wall before forced reset initiates.

• Manufacturer: Rare Breed. Category: Triggers. This unit is machined from billet 4140 steel with a QPQ corrosion-resistant finish for longevity in adverse conditions.
• Drop-in installation for SEF lower housings: Requires no permanent modification to the HK MP5, MP5K, SP5, or SP5K. Ships with all necessary springs, pins, and instructions for end-user installation.
• Patent-pending forced-reset cam system: Utilizes a rotating cam that interacts with the bolt carrier to mechanically reset the trigger sear after each cycle, ensuring positive reset even under rapid manipulation.

Who It’s For

This trigger system is intended for experienced HK platform owners who demand advanced mechanical functionality from their MP5, MP5K, SP5, or SP5K. It is designed for competitive shooters, firearms enthusiasts, and collectors seeking a documented, specification-driven trigger upgrade that provides a distinct firing cycle. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is not a novelty item; it is a precision-engineered component for users who understand roller-delayed blowback operation and desire a repeatable, mechanically forced-reset system. This product is not recommended for novice shooters or those unfamiliar with forced-reset trigger mechanics.

Shipping & FFL

This product is classified as a firearm trigger assembly and is not a firearm frame or receiver. No Federal Firearms License (FFL) transfer is required for shipment to your address in most jurisdictions. However, it is the sole responsibility of the purchaser to verify that the FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is legal to own and install in their specific state, county, and municipality. Rare Breed and this retailer do not assume liability for local compliance. Check all applicable laws and regulations before ordering. Shipment will be made via a common carrier with adult signature required. We reserve the right to delay or cancel orders at our discretion based on legal review. No returns or exchanges on installed trigger components.