Description

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

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K represents a precision-engineered upgrade for the roller-delayed blowback platform. Manufactured by Rare Breed, this trigger system is designed to provide a distinct mechanical cycling characteristic without modifying the host firearm’s lower receiver group. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K employs a two-stage, three-position selector mechanism that integrates forced-reset functionality within a drop-in configuration. This component is intended for shooters who require consistent trigger reset behavior and a defined stage break under rapid firing sequences.

Overview

The FRT-RD3™ (SEF) trigger system uses a proprietary cam and sear engagement geometry to produce a forced-reset cycle. In the standard semi-automatic position, the trigger operates as a traditional two-stage unit with a take-up wall and a crisp break. When engaged in the forced-reset position, the trigger blade is mechanically pushed forward after each shot, requiring the shooter to maintain forward pressure on the trigger to cycle the next round. This design is fully contained within the SEF (Squad Automatic Weapon / Einschiessen Feuerstoss) trigger housing geometry, compatible with HK MP5, MP5K, SP5, and SP5K platforms. The unit replaces the entire trigger pack and requires no permanent modifications to the host firearm.

Features & Specs

• Two-Stage Forced Reset Mechanism: The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K incorporates a two-stage pull with a defined first stage take-up (approximately 2.5 lbs) and a second stage break (approximately 4.5 lbs total pull weight). The forced-reset function activates only in the third selector position.
• Three-Position Selector: The unit offers safe, semi-automatic, and forced-reset positions. The selector detents are machined from billet steel and interface directly with the existing SEF safety detent channels in HK-pattern lowers.
• Drop-In Compatibility: The FRT-RD3™ (SEF) trigger pack is a complete assembly including the trigger blade, hammer, disconnector, sear, and all springs. It installs directly into MP5, MP5K, SP5, and SP5K lower receivers without fitting, filing, or aftermarket parts.

• Material Specifications: The trigger and hammer are machined from 4140 steel, case-hardened to 58-60 HRC. All pins are 4130 chromoly steel with a black oxide finish. Springs are ASTM A228 music wire, heat-set to prevent fatigue.
• Reset Travel: 0.050-inch measured reset distance in semi-automatic mode; forced-reset mode provides positive mechanical forward return of the trigger blade at 0.080-inch overtravel.
• Weight: 3.2 ounces (complete trigger pack assembly).

• Safety Interlock: The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K includes a passive hammer block that prevents the hammer from releasing unless the bolt is fully closed and the trigger is intentionally pulled through its full range of motion.
• No Modification Required: Installation requires no drilling, welding, or replacement of factory pins. The unit uses standard HK push-pins and retains factory hammer spring tension.

Who It’s For

This trigger is designed for experienced HK platform owners who seek a deliberate mechanical cycling behavior without altering the firearm’s original roll stamp or NFA classification. It is suitable for competitive shooters, advanced recreational users, and collectors who maintain a technical understanding of trigger dynamics and mechanical reset systems. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is not recommended for first-time firearm owners or users unfamiliar with forced-reset trigger manipulation. Proper training in trigger discipline and firing sequence management is strongly advised before installation.

Shipping & FFL

This product is classified as a firearm component and does not require a Federal Firearms License (FFL) for purchase. It ships directly to any residential or business address within the United States where state and local laws permit possession of such components. Some states impose restrictions on forced-reset trigger mechanisms; it is the buyer’s responsibility to verify compliance with applicable state and municipal statutes before ordering. Rare Breed and the retailer assume no liability for non-compliance with local regulations. Standard shipping methods apply; no signature is required for delivery unless specified at checkout. For any questions regarding compatibility with specific HK variants or installation requirements, contact the manufacturer directly prior to purchase.