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

Rare Breed has engineered the FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K to meet the demands of advanced shooters operating in the roller-delayed blowback platform. This trigger system is designed specifically for SEF (Schießeinrichtung Einzelfeuer) trigger housing configurations, providing a direct drop-in upgrade for HK-pattern firearms chambered in 9mm. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K utilizes a mechanical forced-reset function that returns the trigger forward immediately after each shot, enabling rapid follow-up shots without modifying the firearm’s internal bolt carrier group. Each unit is precision-machined from billet steel and coated with a corrosion-resistant finish for sustained performance under high-round-count conditions.

Overview

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is a direct replacement trigger pack that fits standard SEF trigger housings found on HK MP5, MP5K, SP5, and SP5K models. It operates on a three-position selector: safe, semi-automatic, and forced-reset mode. In forced-reset mode, the trigger mechanism uses the recoil impulse to mechanically reset the trigger shoe forward, allowing the shooter to fire again as soon as the bolt returns to battery. This design does not rely on aftermarket bolt carriers, buffer systems, or external power sources. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is manufactured in the United States by Rare Breed and complies with all applicable ATF regulations as a non-automatic trigger system.

Features & Specs

• Mechanical forced-reset trigger with two-stage pull: first stage take-up of approximately 2.5 pounds, followed by a crisp second-stage break at 4.5 pounds total pull weight (measured at sear engagement)
• Three-position selector with marked positions for Safe (S), Semi-Automatic (1), and Forced Reset (3); ambidextrous selector shaft compatible with standard HK SEF grip modules
• Drop-in installation: replaces factory trigger pack without permanent modification to the host firearm; includes all necessary springs, pins, and selector lever
• Constructed from 4140 steel with QPQ nitride finish; sear surfaces are EDM wire-cut for consistent engagement angles
• Compatible with HK MP5, MP5K, SP5, SP5K, and all clones utilizing SEF trigger housing geometry (including PTR 9 series and Zenith ZF-5)
• Rated for 9mm Parabellum ammunition only; not compatible with .22 LR conversion kits or other calibers

Who It’s For

This trigger system is intended for experienced shooters who own HK-pattern 9mm carbines or pistols and require a trigger that delivers faster shot-to-shot recovery without converting their firearm to full-automatic operation. The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is appropriate for competitive shooters in USPSA PCC divisions, tactical training environments, and enthusiasts who prioritize trigger control and mechanical consistency. It is not recommended for novice shooters, general home defense applications, or any use where standard semi-automatic trigger function is preferred. Users should have a clear understanding of forced-reset trigger operation and manual safety engagement before use.

Shipping & FFL

This product is classified as a firearm component and does not require transfer through a Federal Firearms License (FFL) dealer for shipment within the United States. However, the FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K may be subject to state or local laws regarding trigger systems with forced-reset functionality. It is the customer’s sole responsibility to verify that this product is legal to own in their jurisdiction before placing an order. Rare Breed triggers are not available for shipment to California, Connecticut, Hawaii, Massachusetts, New Jersey, New York, Rhode Island, Washington D.C., or any locality with statutes prohibiting forced-reset triggers. Standard shipping applies; allow 3-5 business days for processing. All sales are final.