Rare Breed FRT-MR3 Forced Reset Trigger for HK MR223 / MR556 – Curved, 3-Position
Original price was: $525.00.$450.00Current price is: $450.00.
Rare Breed’s forced reset trigger made for the HK MR223 and MR556, with a curved shoe. Runs with the factory semi-auto carrier.
- 3-position Safe / Semi / FRT
- No carrier swap needed
- A1 and A4 drums included
- Made in the USA
- Free shipping3–5 business days, ships from Texas
- Legal states onlySee where we ship
- 30-day returnsOn unused, uninstalled items. Policy
- Help before you buyText (940) 217-4704
Check compatibility first: read the requirements in the description below. Installed triggers can’t be returned, so text us if you’re unsure.
The Rare Breed FRT-MR3 is a 3-position forced reset trigger built specifically for the HK MR223 and MR556, with a curved shoe. Unlike AR-15 FRTs, it is engineered around the factory semi-auto bolt carrier these rifles ship with, so there is no carrier swap.
- Made for HK MR223 / MR556
- Works with the factory semi-auto carrier
- 3-position ambi selector: Safe / Semi / FRT
- Curved shoe, single-stage pull
- A1 and A4 selector drums included
- Made in the USA
The FRT Built for HK’s AR-Pattern Rifles
HK’s MR223 and MR556 are AR-pattern rifles with their own internal differences, which is why a standard AR-15 FRT isn’t the right choice. The FRT-MR3 is designed to run with the factory carrier, buffer and recoil spring, so you keep your rifle’s setup exactly as HK built it.
Prefer the other shoe? The FRT-MR3 Flat is identical apart from the trigger shoe. Running an MP5 or SP5 instead? See the FRT-RD3 and our HK & MP5 FRT collection.
FRT-MR3 Specifications
| Brand | Rare Breed Triggers |
|---|---|
| Model | FRT-MR3 |
| Platform | HK MR223 / MR556 |
| Selector | 3-position, ambidextrous |
| Trigger shoe | Curved |
| Pull | Single-stage |
| Materials | 7075 anodized aluminum, heat-treated 4140 and S7 steel |
| Origin | Made in the USA |
| Patents | U.S. Pat. 10,514,223; 11,724,003; 12,036,336; 12,274,807 |
| SKU | FTS-RB-MR3-CRV |
Compatibility & Requirements
- HK MR223 and HK MR556 with the factory semi-auto bolt carrier
- Manufacturer recommends keeping the factory buffer and recoil spring
- Not intended for standard AR-15s; for those, see the FRT-15L3
What’s in the Box
- 1 x FRT-MR3 trigger assembly
- 1 x A1 selector drum
- 1 x A4 selector drum
- 2 x selector lever roll pins
- 2 x anti-walk pins with 4 x screws
- 2 x T10 Torx wrenches
Compare Similar Options
- Rare Breed FRT-MR3 – FlatSame trigger with a flat shoe.
- AS Designs ARC-Fire V2Selector-based option that also supports the MR556.
- Rare Breed FRT-RD3 (AMBI)For HK MP5 / SP5 roller-delayed firearms.
- HK & MP5 FRT collectionEvery HK-pattern FRT we carry.
FRT-MR3 FAQs
Does the FRT-MR3 fit a standard AR-15?
It is designed for the HK MR223 and MR556. For a standard AR-15, choose an AR-15 FRT such as the Rare Breed FRT-15L3.
Do I need a full-auto bolt carrier for the FRT-MR3?
No. The FRT-MR3 is designed to work with the factory semi-auto bolt carrier in the MR223 and MR556.
Why are two selector drums included?
The kit includes A1 and A4 selector drums so you can match the selector setup you prefer on your rifle.
Why Buy From FRT Trigger LLC
- Free 3–5 day shipping on every order, from Wichita Falls, Texas. Shipping details
- Help before you buy: text (940) 217-4704 with your make and model.
- 10% off your first order with code FRTTEXAS10, or 20% with crypto. See coupons
- Buying several? Save up to 40% with wholesale pricing.
Unused, uninstalled items can be returned within 30 days. Refund policy.
Forced reset triggers are restricted in some states. We do not ship FRTs to California, Colorado, Connecticut, Delaware, Hawaii, Illinois, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island, Washington or Washington, D.C. Please confirm your local laws before ordering. See state restrictions. This is general information, not legal advice.
Learn more: What is a forced reset trigger? · How an FRT works · FRT trigger types · Pros and cons of FRTs
