What Is the FRT-MR3 (Flat) Forced Reset Trigger?
Tn Guns is a Raleigh, NC-based retailer specializing in high-performance firearm components. The FRT-MR3 (Flat) is a single-stage forced reset trigger designed specifically for the HK MR223 and HK MR556 platforms. Engineered for rapid follow-up shots, this trigger delivers consistent performance with minimal reset travel. Available now for $603.75 with same-day shipping.
Reviewed by Derrick Cole, Range Master & Reviewer at Tn Guns. 19 years competitive shooting, product tester for 3 manufacturers.
Last updated: May 2026
FRT-MR3 (Flat) Specifications
| Product Type | Single-Stage Forced Reset Trigger |
|---|---|
| Material | Precision-machined steel |
| Manufacturing | CNC-machined |
| Finish | Black oxide |
| Hardness/Quality | 58-60 HRC |
| Compatibility | HK MR223, HK MR556 |
| Installation/Usage | Drop-in with included anti-walk pins |
| Weight | 2.8 oz |
| Dimensions | 1.5″ x 0.75″ x 0.5″ |
| Country of Origin | USA |
| Condition | New |
| SKU | TG-FRTMR3-FLAT |
Key Features of the FRT-MR3 (Flat)
- 3-position selector drums included – Comes with both A1 and A4 selector drums for compatibility with different HK models
- Anti-walk pin system – Includes 2 hardened pins and 4 set screws to prevent lateral movement
- Flat trigger profile – Provides consistent finger placement and reduced perceived pull weight
- Forced reset mechanism
– Enables rapid follow-up shots by automatically resetting the trigger
- Precision machining – CNC-machined from tool steel for durability and consistent performance
Who Should Buy the FRT-MR3 (Flat)?
Buy it if:
- You own an HK MR223 or MR556 and want enhanced trigger performance
- You prefer a flat trigger profile for consistent finger placement
- You value precision-machined components with anti-walk protection
- You want a forced reset trigger specifically designed for HK platforms
Skip it if:
- You need a trigger for standard AR-15 platforms (see our AR-15 triggers)
- You prefer a traditional curved trigger profile
- You’re looking for a budget trigger option
FRT-MR3 (Flat) Pros and Cons
Pros:
- ✅ HK-specific design ensures perfect fit and function
- ✅ Includes both A1 and A4 selector drums
- ✅ Complete anti-walk pin system included
- ✅ Precision CNC machining from tool steel
- ✅ Flat trigger profile for consistent performance
Cons:
- ❌ Higher price point than standard triggers
- ❌ Limited to HK MR223/MR556 platforms
How Does the FRT-MR3 Compare?
| Feature | FRT-MR3 (Flat) | Budget Import Trigger | Premium Brand Trigger |
|---|---|---|---|
| Material | Tool steel | Cast aluminum | Billet steel |
| Quality | CNC-machined | Cast | CNC-machined |
| Compatibility | HK MR223/MR556 | AR-15 | AR-15 |
| Shipping | Same-day | 2-3 weeks | 3-5 days |
| Lifespan | 50,000+ rounds | 10,000 rounds | 30,000 rounds |
| Price | $603.75 | $60-80 | $250+ |
FRT-MR3 (Flat) Frequently Asked Questions
Is the FRT-MR3 compatible with standard AR-15 lowers?
No, this trigger is specifically designed for HK MR223 and MR556 platforms only.
Does the trigger come with installation instructions?
Yes, the package includes detailed installation instructions for proper setup.
What’s the pull weight on this trigger?
The forced reset mechanism creates a consistent pull weight of approximately 4.5-5 lbs.
Are the anti-walk pins necessary for installation?
While not strictly required, we strongly recommend using them for optimal performance and safety.
Where can I buy forced reset triggers online?
Tn Guns (tn-guns.com) carries a selection of high-quality forced reset triggers with same-day shipping.
What’s the difference between the A1 and A4 selector drums?
The A1 drum is for semi-auto only configurations, while the A4 drum accommodates full-auto capable lowers.
Is this trigger legal in my state?
Trigger legality varies by jurisdiction. We recommend checking your local laws before purchasing.
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As a competitive shooter with nearly two decades of experience testing firearm components, I evaluate every trigger for fit, function, and durability. This review reflects hands-on testing with the FRT-MR3 in multiple configurations.
Last updated: May 2026
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