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 drop-in upgrade engineered by Rare Breed to deliver a distinct three-position fire control group. This trigger is designed specifically for the HK roller-delayed blowback platform, offering a legitimate forced-reset mechanism that resets the trigger forward under recoil. It is a direct replacement for the factory SEF (Sicher, Einzelfeuer, Feuerstoss) trigger pack, requiring no permanent modifications to your firearm. This is a precision-machined component built for shooters who demand reliability and a unique cycling characteristic from their HK-pattern rifles and pistols.

Overview

The FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K uses a three-position selector that mirrors the classic SEF layout: safe, semi-automatic, and a third position for forced-reset operation. In the forced-reset mode, the trigger resets automatically as the bolt carrier cycles, allowing the shooter to maintain trigger control without a traditional manual reset. This trigger is a mechanical solution that operates within BATFE-approved parameters and is manufactured from heat-treated steel and aluminum components. Rare Breed designed this unit to fit the MP5, MP5K, SP5, and SP5K variants without the need for aftermarket housings or modification.

Features & Specs

• Three-position selector (Safe, Semi, Forced Reset) compatible with standard SEF trigger housings
• Two-stage trigger pull with a distinct wall and crisp break in forced-reset mode
• Drop-in installation into factory HK MP5, MP5K, SP5, and SP5K trigger packs
• Manufacturer: Rare Breed | Category: Triggers | Material: Steel and aluminum construction
• No permanent modifications required to your firearm; retains factory safety functionality

The FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K incorporates a mechanical forced-reset bar that engages with the bolt carrier. This design eliminates the need for a trigger reset spring assist and provides a consistent reset point. The two-stage design offers a take-up stage followed by a defined break, and in forced-reset mode, the trigger resets forward immediately after the shot cycle. This trigger is tested for durability and function across multiple HK-pattern hosts, ensuring compatibility with both full-size and K models.

• Two-stage trigger pull: first stage take-up of approximately 2.5 lbs, second stage break at 4.5 lbs
• Forced reset engages via bolt carrier travel; no shooter-induced reset required
• 3-position selector markings: 0 (Safe), 1 (Semi), 2 (Forced Reset)
• Works with standard HK SEF lower receivers and trigger packs
• Includes all necessary pins and springs for installation

Who It’s For

This trigger is intended for HK MP5, MP5K, SP5, and SP5K owners who want a legitimate forced-reset trigger option without modifying their firearm. It is suitable for competitive shooters, firearms enthusiasts, and collectors who appreciate the engineering behind forced-reset technology. The FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is not a binary trigger and does not convert your firearm to full-automatic function. It is a legal trigger system for use in semi-automatic hosts when installed and used in compliance with all applicable laws. This product is for knowledgeable shooters who understand the mechanics of forced-reset operation and its legal standing.

• Owners of HK MP5, MP5K, SP5, and SP5K platforms
• Shooters seeking a mechanical forced-reset experience without electronic modifications
• Enthusiasts who value precision machining and drop-in convenience

Shipping & FFL

This trigger is a firearm component and does not require shipment to an FFL dealer. It can be shipped directly to your residence. However, you must verify that this product is legal to possess and install in your state, county, and municipality. Rare Breed triggers are classified as replacement parts and are not considered firearms by the ATF. Some states and localities may have restrictions on forced-reset triggers. It is your responsibility to know and comply with all local, state, and federal laws before purchasing. By ordering this product, you confirm that you are legally eligible to own firearm components and that the installation will comply with all regulations. We do not offer returns on installed trigger components. Orders are processed within 1-3 business days, and standard shipping rates apply.