FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K

If you own an HK roller-delayed platform in the MP5, MP5K, SP5, or SP5K family, you already know the stock trigger leaves room for improvement. That single-stage, mushy pull might be fine for plinking, but for serious shooters who want speed without sacrificing control, the FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger from Rare Breed is a genuine upgrade. This isn’t just another drop-in part; it’s a purpose-built forced reset trigger designed specifically for the HK small-frame pattern. The FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K brings a two-stage pull and three-position selector functionality to your favorite roller-lock, giving you a crisp break and a controlled reset that keeps your finger on the trigger without slapping the shoe.

Overview

The FRT-RD3 is Rare Breed’s answer to the demand for a reliable, semi-automatic forced reset trigger that works with the unique geometry of HK’s MP5-series lower receivers. It uses a standard SEF (Sicher, Einzelfeuer, Feuerstoss) trigger housing pattern, meaning it drops directly into your factory or aftermarket SEF lower without permanent modifications. The trigger features a two-stage pull: a light take-up stage followed by a wall, then a crisp break. The forced reset mechanism uses the bolt’s forward movement to physically reset the trigger shoe, allowing for rapid follow-up shots while maintaining semi-automatic compliance. The three-position selector provides safe, semi-automatic, and an additional setting that optimizes the forced reset cycle for the fastest legal fire rate the platform can handle. Every component is machined from billet steel and hardcoat anodized for durability under heavy use.

Features & Specs

• Two-stage trigger pull with a distinct wall and crisp break, designed specifically for the HK MP5, MP5K, SP5, and SP5K roller-delayed blowback system.
• Three-position SEF selector (Safe, Semi, Forced Reset) that works with factory HK or aftermarket SEF trigger housings without additional modification.
• Forced reset technology uses bolt carrier movement to reset the trigger shoe, enabling consistent, rapid semi-automatic fire with a short, predictable reset.

Specs: Rare Breed FRT-RD3, Category: Triggers. Fits HK MP5, MP5K, SP5, SP5K with SEF trigger housing. Drop-in installation with standard pins. Constructed from billet steel with hardcoat anodized finish. This forced reset trigger is built for the shooter who demands reliability from a component that sees thousands of rounds in a single session.

• No permanent modification required to your host firearm; swaps easily between lowers if you have multiple MP5 variants.
• Optimized for 9mm roller-lock platforms; tested extensively with factory ammunition to ensure consistent forced reset function.
• Includes all necessary pins and springs for a complete trigger pack installation in your SEF lower.

Who It’s For

This trigger is for the HK enthusiast who has already invested in the roller-delayed system and wants to push the platform’s performance in a legal, semi-automatic configuration. It’s for the competitor running an SP5 in USPSA or PCC divisions who needs a clean two-stage break and a fast reset without the mush of a factory pack. It’s also for the collector who wants to experience the mechanical innovation of a forced reset trigger in a classic roller-lock design. If you own an MP5, MP5K, SP5, or SP5K and you’ve been shopping for a trigger that combines a two-stage pull with forced reset technology, the FRT-RD3 (SEF) Two-Stage (3-Position) Forced Reset Trigger for the HK MP5, MP5K, SP5 & SP5K is the specific component you’re looking for. It’s not a gimmick; it’s a functional upgrade for shooters who know what they want from their trigger.

Shipping & FFL

This trigger is classified as a firearm component and ships directly to your door. No federal firearms license (FFL) is required for purchase or delivery. However, you must be at least 18 years of age to order and must comply with all local, state, and federal laws regarding firearm parts. It is your responsibility to verify that this component is legal to own in your jurisdiction. Rare Breed triggers are designed for semi-automatic use only and are compliant with current BATFE regulations as of the date of manufacture. We strongly recommend checking your local laws before placing an order, as some states or municipalities may have restrictions on forced reset triggers or certain trigger mechanisms. By purchasing this product, you certify that you are legally eligible to own firearm components and that you will not use this trigger in any configuration that violates applicable law. We do not ship to states or localities where this product is prohibited.