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

If you have ever run an HK roller-delayed platform hard, you know the trigger is where the magic happens–or where it stalls. The FRT-RD3 (ambi) two-stage (3-position) forced reset trigger for the HK MP5, MP5K, SP5 & SP5K brings Rare Breed’s proven forced-reset engineering to the iconic roller-locked family. This is not a drop-in gimmick; it is a carefully machined trigger system that changes how you interact with the reset without altering your firearm’s semi-automatic classification. We have put several hundred rounds through our test gun, and the ambi safety selector paired with the two-stage break makes this an intuitive upgrade for both righties and lefties.

Overview

The FRT-RD3 uses a three-position selector: safe, semi-auto, and a forced-reset mode that returns the trigger face forward immediately after each shot. Unlike a standard single-stage trigger, the two-stage design gives you a defined take-up wall before the break, which helps when you are shooting from a barricade or making precision hits between fast strings. This trigger is machined from billet steel and treated with a corrosion-resistant finish that holds up to carbon fouling and solvent. It fits HK MP5, MP5K, SP5, and SP5K models without permanent modification to the receiver. The ambidextrous safety lever is included, so you can run it with your support-hand thumb or swap it to your preferred side.

Features & Specs

• Three-position ambidextrous selector: safe, semi-auto, forced-reset mode
• Two-stage trigger pull with a distinct take-up wall and crisp break
• Machined from billet steel with a matte black oxide finish for corrosion resistance
• Includes ambidextrous safety lever, trigger, hammer, sear, and all necessary pins
• Drop-in design for HK MP5, MP5K, SP5, and SP5K variants–no receiver modification required

The forced-reset function works by using the bolt’s forward travel to push the trigger face back into position. This means you must maintain firm finger contact through the entire cycle; if you lift your finger, the trigger will not reset. It takes a few magazines to build the muscle memory, but once you do, the cadence feels natural and repeatable. Rare Breed has designed the FRT-RD3 (ambi) two-stage (3-position) forced reset trigger for the HK MP5, MP5K, SP5 & SP5K to function with both factory and aftermarket bolt carriers, though we recommend using a standard-weight carrier for reliable reset.

Who It’s For

• HK roller-lock owners who want to increase their split times without converting to a full-auto trigger pack
• Left-handed shooters who have struggled to find an ambi trigger that doesn’t feel mushy on the support side
• Collectors who own SP5 or SP5K pistols and want a trigger that matches the platform’s mechanical precision
• Competition shooters running PCC divisions that allow forced-reset triggers and need a predictable two-stage break

This trigger is not for someone looking for a light, hair-trigger pull. The two-stage design gives you a heavier initial take-up (around 4.5-5 pounds) and a clean second-stage break. It is for shooters who understand that a forced-reset system requires deliberate finger discipline and who appreciate the mechanical feedback of a trigger that resets with bolt movement rather than spring tension alone. If you have ever shot a standard MP5 trigger and wished for a shorter reset with ambi controls, this is the upgrade you have been waiting for.

Shipping & FFL

This trigger is a firearm component and can be shipped directly to your door within the United States–no FFL transfer required for the trigger assembly itself. However, because the FRT-RD3 is a regulated item in some states and municipalities, you are responsible for verifying local laws before ordering. We ship via UPS Ground with adult signature required. Rare Breed triggers are not available for shipment to California, New York, New Jersey, Massachusetts, Connecticut, Hawaii, or Washington, D.C. If your state or local jurisdiction restricts forced-reset triggers, please do not order. By completing your purchase, you certify that you are legally eligible to own this product and that your local laws permit its possession and use. All sales are final.