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 HK-pattern roller-delayed blowback firearms. Manufactured by Rare Breed, this drop-in trigger system replaces the factory single-stage trigger group to deliver a distinct two-stage pull with a forced-reset operating cycle. Designed exclusively for standard SEF (Sicherheits-Einrichtung-Feuer) lower housings, the FRT-RD3™ provides three selectable positions: Safe, Semi-Automatic, and a third position enabling the forced-reset function. Each unit is CNC-machined from billet steel and hard-coat anodized for durability under sustained use.

Overview

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is a mechanical trigger system that utilizes the bolt carrier’s forward motion to reset the trigger shoe, enabling a faster cycling rate while maintaining semi-automatic functionality. Unlike standard mil-spec triggers, the forced-reset mechanism positively returns the trigger to its forward position after each shot, reducing the time required for the shooter to initiate the next trigger pull. This trigger is compatible with HK MP5, MP5K, SP5, and SP5K models that utilize the SEF trigger housing configuration. The three-position selector allows the user to lock the weapon in Safe, engage standard semi-automatic fire, or activate the forced-reset mode. The trigger pull weight is factory-set to approximately 6.5 pounds on the first stage and 4.5 pounds on the second stage, providing a crisp, predictable break.

Features & Specs

• Two-stage trigger pull: first stage at 6.5 lbs, second stage at 4.5 lbs, with a positive reset and minimal overtravel
• Three-position selector: Safe (S), Semi-Automatic (E), and Forced-Reset (F) positions clearly marked on the housing
• CNC-machined from 4140 steel with a MIL-SPEC Type III hard-coat anodized finish for corrosion resistance and wear longevity

• Drop-in design: no permanent modification required to the host firearm; installs directly into SEF-spec trigger packs for MP5, MP5K, SP5, and SP5K platforms
• Forced-reset mechanism: utilizes bolt carrier forward travel to mechanically reset the trigger, enabling consistent shot-to-shot timing
• Includes all necessary springs, pins, and selector components; assembled and tested at Rare Breed prior to shipment

• Compatible with factory and aftermarket SEF trigger housings; does not require specialized tools for installation
• Operating temperature range: -20°F to 160°F; tested for function across extreme environmental conditions
• Weight: 3.2 ounces (complete trigger group assembly); manufactured in the United States

Who It’s For

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is intended for experienced shooters who require a higher cyclic rate from their HK-pattern platform while retaining semi-automatic legal classification. This product is suited for competitive shooters in action shooting sports, firearms instructors demonstrating advanced trigger manipulation, and collectors who maintain SEF-configured MP5 variants. It is not recommended for new shooters due to the specific handling requirements of forced-reset triggers. Users must verify that their firearm is configured with an SEF trigger housing before purchase, as the FRT-RD3™ will not function in Navy-style (ambidextrous) or push-pin lower receivers without adapter modifications.

Shipping & FFL

This FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is classified as a firearm component and is not a regulated firearm receiver. It ships directly to the customer’s billing address with adult signature required upon delivery. Standard shipping rates apply; expedited options are available at checkout. International shipments are not available. The end user assumes full responsibility for compliance with all applicable federal, state, and local laws regarding the installation and use of aftermarket trigger systems. As with all trigger components, Rare Breed recommends installation by a certified gunsmith. This item is not restricted by the National Firearms Act (NFA), but some jurisdictions may impose restrictions on forced-reset trigger mechanisms. It is the purchaser’s obligation to verify legality in their location prior to ordering. No FFL transfer is required for this trigger assembly.