FRT-RD3™ (AMBI)

Two-Stage 3-Position Forced Reset Trigger for HK MP5, MP5K, SP5 & SP5K Platforms

Upgrade your HK roller-delayed platform with the official Rare Breed Triggers FRT-RD3™ (AMBI) — a premium drop-in two-stage forced reset trigger engineered specifically for HK MP5, MP5K, SP5, SP5K, and compatible roller-delayed firearm platforms.

Manufactured and assembled in the USA, the FRT-RD3™ (AMBI) delivers advanced trigger performance, precision engineering, and reliable operation with a design built specifically around HK roller-delayed systems.

Featuring a 3-position selector system with Safe, Semi-Automatic, and Forced Reset Trigger (FRT®) modes, the FRT-RD3™ (AMBI) includes an HK AMBI-style safety selector designed for compatible ambidextrous grip frames.

Advanced Performance for HK Roller-Delayed Platforms

The FRT-RD3™ (AMBI) enhances your shooting experience with innovative forced reset technology designed to improve trigger reset speed, consistency, and control.

The system mechanically resets the trigger after each shot, allowing faster follow-up shots while maintaining individual shot control and a consistent shooting rhythm.

Each trigger pull is designed to fire one round, providing a controlled and predictable experience ideal for competition shooting, training, and range applications.

Key Features

3-Position HK AMBI Selector System

The FRT-RD3™ (AMBI) features a dedicated 3-position HK AMBI-style selector system designed for modern HK ambidextrous grip frames.

Selectable modes include:

• Safe Mode
• Semi-Automatic Mode
• Forced Reset Trigger (FRT®) Mode

The selector design integrates with HK AMBI-style grip frames for a clean, factory-style appearance and operation.

Simple Drop-In Installation

The FRT-RD3™ (AMBI) is engineered for easy installation in compatible HK AMBI grip frames.

Designed as a plug-and-play upgrade, the trigger system provides a streamlined installation process without requiring modifications to compatible firearms.

Two-Stage Trigger Performance

The FRT-RD3™ (AMBI) was designed from the ground up as a dedicated HK roller-delayed trigger system, providing a refined two-stage trigger experience.

The optimized geometry delivers:

• Smooth first-stage take-up
• Clean, crisp second-stage break
• Consistent trigger reset
• Improved trigger control

This design ensures proper timing, reliable operation, and compatibility with roller-delayed firearm systems.

Built for Durability & Reliability

The FRT-RD3™ (AMBI) is constructed using premium materials engineered for long-term performance:

• 7075 anodized aluminum
• Heat-treated 4140 steel components

Built to withstand demanding use, the FRT-RD3™ (AMBI) provides the durability and reliability expected from a premium HK platform upgrade.

HK MP5 / SP5 Platform Compatibility

The FRT-RD3™ (AMBI) is specifically engineered for HK roller-delayed platforms, including:

• HK MP5
• HK MP5K
• HK SP5
• HK SP5K

The trigger system is designed to operate with the factory semi-automatic bolt carrier used in these platforms.

Compatible models include firearms equipped with factory full-auto carrier denial blocks in the receiver, requiring no firearm modifications.

For additional versatility, the FRT-RD3™ (AMBI) is also compatible with full-auto bolt carrier groups; however, a full-auto carrier is not required for operation.

HK AMBI Grip Frame Compatibility

The FRT-RD3™ (AMBI) is designed for HK AMBI-style grip frames, commonly identified by modern pictogram markings.

These grip frames feature:

• Selector levers on both sides
• Bullet-style pictogram markings
• Forward-facing selector axle indicator

The included selector system is designed to integrate with this configuration for a proper fit and function.

Speed, Precision & Control

The FRT-RD3™ (AMBI) is engineered for shooters seeking improved performance from their HK roller-delayed firearm.

By mechanically resetting the trigger after each shot and locking the trigger until the bolt carrier group returns to battery, the system enables faster follow-up shots without requiring advanced shooting techniques.

The forced reset mechanism returns the trigger to the ready position after each round, requiring a separate trigger pull while maintaining complete shooter control.

Why Choose the FRT-RD3™ (AMBI)?

The FRT-RD3™ (AMBI) is the ultimate trigger upgrade for shooters looking to maximize the performance of their HK MP5, MP5K, SP5, or SP5K platform.

Combining HK-specific engineering, two-stage trigger performance, durable construction, and forced reset technology, the FRT-RD3™ (AMBI) delivers a premium shooting experience for competition, training, and range applications.

Unlock the full potential of your HK roller-delayed platform with the FRT-RD3™ (AMBI).

Manufactured & Assembled in the USA