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 significant advancement in trigger system engineering for the roller-delayed blowback platform. Manufactured by Rare Breed, this trigger assembly transforms the standard semi-automatic firing cycle into a forced-reset action that demands deliberate finger control. Designed specifically for MP5, MP5K, SP5, and SP5K variants, the FRT-RD3™ integrates a true two-stage trigger pull with a mechanical forced-reset mechanism that returns the trigger forward immediately after each shot, enabling rapid follow-up shots without modification to the host firearm’s fire control group geometry.

Overview

The frt-rd3™ (sef) two-stage (3-position) forced reset trigger for the hk mp5, mp5k, sp5 & sp5k is a drop-in replacement unit that utilizes the standard SEF (Sicher/Feuer) lower frame. It operates across three distinct positions: safe (S), semi-automatic (E), and forced-reset (F). In the forced-reset position, the trigger mechanism mechanically pushes the trigger shoe forward after each hammer release, requiring the shooter to maintain constant rearward pressure to cycle the action. This is not a binary trigger system; it is a forced-reset design that relies on the shooter’s trigger finger to complete the cycle. Rare Breed engineered this unit using CNC-machined steel components and hardened internal sears to withstand the high cyclic rates associated with forced-reset operation.

Features & Specs

• Two-stage trigger pull: first stage take-up measures 2.5 to 3.0 pounds, second stage break at 4.0 to 4.5 pounds (measured at the trigger shoe) with a crisp, repeatable wall before reset.
• Three-position selector: safe (S), semi-automatic (E), and forced-reset (F) with positive detent engagement at each position; fully compatible with HK SEF trigger housings and grip frames.
• Mechanical forced-reset cam: integrated cam follower and reset spring assembly that initiates trigger return within 0.010 inches of hammer release, independent of bolt carrier travel.

• Material composition: 4140 steel hammer and sear, 7075-T6 aluminum trigger housing plate, and 17-4 PH stainless steel cam pin; all components are salt bath nitride treated for corrosion resistance and reduced friction.
• Drop-in installation: no permanent modification to the factory trigger pack, no drilling, and no sear replacement required; compatible with all HK MP5, MP5K, SP5, and SP5K variants utilizing SEF lower receivers.
• Legal classification: classified as a semi-automatic trigger system by the ATF (FTB determination letter available upon request); does not convert firearm to full-automatic or burst-fire capability.

Who It’s For

This frt-rd3™ (sef) two-stage (3-position) forced reset trigger for the hk mp5, mp5k, sp5 & sp5k is intended for experienced shooters who demand maximum trigger control at elevated firing rates. It is suitable for competition shooters in USPSA Open division, PCC shooters requiring rapid split times, and advanced enthusiasts who understand the mechanical principles of forced-reset operation. The unit is not recommended for novice shooters, law enforcement duty use, or suppressed applications where bolt velocity may exceed the reset timing window. Users should have a thorough understanding of trigger discipline and manual of arms for three-position selector systems before installation. The forced-reset function requires deliberate finger management and is not a set-and-forget device; it demands active shooter participation with each trigger pull.

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 your doorstep. No Federal Firearms License (FFL) transfer is required for purchase or delivery. However, you must comply with all applicable federal, state, and local laws regarding trigger systems and firearm modifications. Some states, including but not limited to California, New York, New Jersey, Connecticut, Massachusetts, Hawaii, and Washington D.C., may impose restrictions on forced-reset trigger systems. It is your sole responsibility to verify legality in your jurisdiction before ordering. Rare Breed recommends consulting with a qualified firearms attorney if you have questions regarding compliance. By purchasing this product, you acknowledge that you are not prohibited from owning firearms or firearm components under federal law.