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 drop-in trigger assembly introduces a two-stage, three-position selector system that integrates forced reset functionality into the classic HK trigger pack housing. Designed specifically for the MP5, MP5K, SP5, and SP5K variants equipped with the Single Edge Fire (SEF) grip configuration, this trigger system delivers a distinct mechanical cycling profile without modifying the host firearm’s receiver or bolt group.

Overview

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K redefines the trigger interface for these iconic sub-machine gun and pistol-caliber carbine platforms. This unit replaces the factory trigger pack entirely, utilizing a three-position selector that corresponds to Safe, Semi-Automatic, and the forced-reset mode. The forced-reset mechanism uses the bolt carrier’s forward travel to physically reset the trigger sear, enabling a repeatable firing cycle that is mechanically governed by the shooter’s trigger manipulation. Rare Breed has engineered this trigger to maintain the stock safety functionality and standard semi-automatic operation while adding the third position as a distinct firing mode.

Features & Specs

• Three-position selector (Safe, Semi-Automatic, Forced Reset) designed for HK MP5, MP5K, SP5, and SP5K models with SEF grip housings. The forced reset mode requires the shooter to maintain trigger finger pressure through the reset point to cycle the next round.
• Two-stage trigger pull geometry: a defined take-up stage followed by a crisp break at the sear release point. The forced reset function engages during the bolt carrier’s return to battery, providing tactile and audible feedback to the operator.
• Drop-in installation into factory HK or HK-licensed trigger housings. No permanent modifications, filing, or drilling required to the receiver or lower assembly. Compatible with standard HK safety selector levers and grip modules.

Manufacturer: Rare Breed | Category: Triggers | Platform: HK MP5, MP5K, SP5, SP5K (SEF configuration only)

• Heat-treated alloy steel sear components with precision-ground engagement surfaces. The disconnector and trigger bar are machined to tight tolerances to ensure consistent forced reset timing across varying cyclic rates.
• Nickel-Teflon coated internal contact surfaces for reduced friction and corrosion resistance. The coating is applied to the hammer, sear, and trigger bar sliding surfaces.
• Factory-assembled trigger pack unit includes all springs, pins, and retaining clips. The pack is test-fired at the manufacturer prior to shipment.

Who It’s For

The FRT-RD3™ (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is designed for experienced shooters who operate roller-delayed blowback firearms and seek an alternative trigger interface that rewards precise finger control. It suits competitive shooters in practical shooting disciplines that allow forced reset technology, as well as collectors and enthusiasts who wish to explore the mechanical behavior of this specific trigger system. This product is not intended for novice users or those unfamiliar with forced reset trigger dynamics. Users must have a thorough understanding of their local, state, and federal regulations regarding trigger mechanisms and firing modes. The forced reset mode requires deliberate practice to achieve consistent cycling and should only be used on ranges that permit such systems.

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 ships directly to the buyer’s address. No Federal Firearms License (FFL) transfer is required for this trigger pack as it is not a firearm receiver or complete firearm. However, it is the sole responsibility of the purchaser to verify that this product is legal to own and install in their jurisdiction. Some states and municipalities have enacted restrictions on forced reset triggers or triggers with selectable firing modes. By purchasing this item, the buyer affirms compliance with all applicable laws. Rare Breed and the retailer assume no liability for misuse or improper installation. Standard shipping rates apply; expedited options are available at checkout. Inspect the trigger pack upon receipt and report any damage within 48 hours.