FRT-MR3™ (FLAT) Single-Stage (3-Position) Forced Reset Trigger for the HK MR223 & HK MR556

The official Rare Breed FRT-MR3™ (FLAT) — a single-stage, flat, 3-position (Safe / Semi / FRT®) forced reset trigger for the HK MR556 & MR223, 100% made in the USA. Drop-in, duty-grade and backed by our warranty. Buy the original FRT trigger for sale direct from the patent holder.

$525.00

Description

Rare Breed FRT-MR3™ (FLAT) — flat-shoe HK MR223 & MR556 forced reset trigger

The duty-grade Rare Breed FRT-MR3™ with a flat trigger face for leverage and a repeatable press. A single-stage, drop-in 3-position FRT trigger (Safe / Semi / FRT®) for the HK MR223 and MR556, 100%% made and assembled in the USA — an authentic FRT trigger for sale for your HK piston rifle.

How the forced reset trigger works

In FRT® mode, the FRT-MR3™ (FLAT) uses your firearm’s own cycling to drive the trigger forward into its reset position after every shot — so your next round is ready almost as soon as the gun is. The result is a dramatically faster, smoother and more consistent shooting cadence than a standard trigger. Crucially, it stays fully semi-automatic: the trigger fires one round per pull of the trigger, every time, and must fully reset before it can fire again. Want the details? Read what a forced reset trigger is and how a forced reset trigger works, or go deeper on the FRT mechanism.

Innovative design and features

  • Duty-grade build engineered for HK’s premium MR223 and MR556 piston rifles.
  • Flat trigger shoe for added leverage and a consistent press.
  • Includes A1 (0/90/180) and A4 (0/45/90) selector bodies for flexible, ambidextrous control.
  • Drop-in installation — no gunsmithing required.

Specifications

Platform HK MR223 & HK MR556
Trigger type Single-stage forced reset trigger
Modes 3-position: Safe / Semi / FRT®
Trigger shoe Flat
Selectors A1 (0/90/180) & A4 (0/45/90) included
Origin Designed & assembled in the USA

What’s in the box

  • 1 × FRT-MR3™ (FLAT) trigger
  • 2 × anti-walk pins
  • 4 × anti-walk pin screws
  • 1 × A1 selector drum
  • 1 × A4 selector drum
  • 2 × selector lever roll pins
  • 2 × T10 Torx wrenches

Choose your FRT-MR3™ configuration

Prefer the curved shoe? See the FRT-MR3™. Want the Mil-Spec selector? See the FRT-MR3™ (MIL).

Why buy your FRT-MR3™ (FLAT) direct from Rare Breed Triggers

When you buy direct, you get the genuine article — not a counterfeit or a grey-market copy. Rare Breed Triggers is the exclusive licensee of the U.S. patents behind forced reset trigger technology, and we pioneered the category with the original FRT-15®. Every FRT-MR3™ (FLAT) FRT trigger for sale here is 100% designed, manufactured and assembled in the USA, backed by our limited warranty, and shipped fast from the patent holder. Beware of fakes: if it isn’t from Rare Breed, it isn’t a real FRT®.

Legal & shipping

Forced reset triggers are legal under federal law following Rare Breed’s court victory and 2025 settlement with the United States — see our FRT legal status for the full picture. Some states restrict FRTs, and we do not ship to those jurisdictions; it is your responsibility to know your local laws. Review our FAQs before you order. (General information, not legal advice.)

Buy the FRT-MR3™ (FLAT) online

Ready to upgrade? Add the FRT-MR3™ (FLAT) to your cart and buy direct from Rare Breed Triggers — the original FRT trigger for sale, in stock and shipping fast. Browse the full HK MR556 & MR223 forced reset triggers or the complete lineup of FRT triggers for sale to find the right trigger for every firearm you own.