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 is a precision-engineered drop-in trigger system from Rare Breed. Designed specifically for the HK roller-delayed blowback platform, this trigger delivers a distinct two-stage pull with a forced-reset function across three selectable positions. It provides shooters with a repeatable, predictable trigger cycle without modifying the host firearm’s lower receiver. This unit is built to military-spec tolerances and is compatible with semi-auto and select-fire rated hosts.

Overview

The FRT-RD3 (SEF) trigger system replaces the factory trigger pack in your HK MP5, MP5K, SP5, or SP5K. It utilizes a forced-reset mechanism that returns the trigger forward immediately after each shot, allowing the shooter to maintain a consistent finger position for rapid follow-up shots. The three-position selector offers safe, semi-automatic, and the forced-reset function. This is not a conversion device; it is a complete trigger assembly that requires no permanent alterations to your firearm. The system is designed for shooters who demand precise control over their trigger reset cycle in a compact PDW or carbine platform.

Every FRT-RD3 (SEF) trigger is manufactured from heat-treated steel and aerospace-grade aluminum components. The housing is CNC-machined to exact HK specifications, ensuring a snug fit that eliminates play. The trigger shoe features a smooth, flat face for consistent finger placement. This trigger is optimized for the unique bolt carrier geometry of the HK roller-delayed system, providing reliable function across suppressed and unsuppressed configurations.

Features & Specs

• Three-position selector: Safe, Semi, and Force Reset (FR) modes. The FR position enables the forced-reset function, where the trigger automatically resets to the wall upon bolt return, requiring only a short, crisp pull for each subsequent shot.
• Two-stage pull: A defined take-up stage transitions into a clean, glass-like break at approximately 4.5 to 5.5 pounds. The reset is tactile and audible, giving the shooter immediate feedback.
• Drop-in installation: No gunsmithing required. The FRT-RD3 (SEF) trigger replaces the existing trigger pack in MP5, MP5K, SP5, and SP5K models with standard SEF (single/double/safe) lower receivers. Includes all necessary springs and pins.

Additional specs from the manufacturer: Rated for continuous use with 9mm Parabellum ammunition. Operating temperature range: -20°F to 160°F. Housing material: 7075-T6 aluminum with Type III hard coat anodizing. Internal components are coated with a proprietary dry-film lubricant for reduced friction. Each unit is individually function-tested before shipment.

Who It’s For

This trigger is intended for experienced HK platform owners who understand the mechanics of forced-reset triggers and seek a purpose-built component for range use, competition, or training. It is not a novelty item; it is a functional upgrade for shooters who want to maximize their cyclic control without converting to a full-auto configuration. The FRT-RD3 (SEF) trigger is compatible with registered select-fire lowers and semi-auto hosts alike. It is not designed for hunting or defensive carry due to the unique manual of arms required for the forced-reset function. Users should have a solid understanding of safe firearm handling and trigger discipline before operating this system.

If you own an MP5, MP5K, SP5, or SP5K and want a trigger that offers a distinct, repeatable reset cycle with a two-stage pull, this is a direct-fit solution. It is also suitable for collectors and enthusiasts building a specific clone or configuration of the HK roller-delayed platform.

Shipping & FFL

This FRT-RD3 (SEF) trigger is classified as a firearm component and does not require transfer through a Federal Firearms License (FFL) dealer for shipment to most states. However, some state or local laws may impose restrictions on the sale or possession of forced-reset trigger systems. It is your responsibility to verify compliance with all applicable laws before purchasing.

We ship to all states where this product is legal. Orders are processed within one business day. Standard shipping is free. Expedited options are available at checkout. This product ships directly to your residential or business address unless your jurisdiction requires an FFL transfer. If you have any questions regarding your state’s regulations, contact us before placing your order. Rare Breed recommends consulting with a qualified firearms attorney if you are uncertain about your legal standing.