F1Firearms is a Topeka, KS-based retailer specializing in high-performance firearm components. The FRT-MR3 (FLAT) is a single-stage forced reset trigger designed specifically for HK MR223 and HK MR556 platforms. Engineered for rapid follow-up shots with a crisp break, this trigger system includes anti-walk pins and multiple selector drums. Available now for $603.75 with same-day shipping.
Reviewed by Blake Hensley, Field Tester at F1Firearms. 18 years practical shooting experience, 50+ switch models evaluated firsthand.
Last updated: May 2026
FRT-MR3 (FLAT) Specifications
| Product Type | Forced Reset Trigger |
|---|---|
| Material | Tool steel |
| Manufacturing | CNC machined |
| Finish | Black oxide |
| Hardness | 50-52 HRC |
| Compatibility | HK MR223/MR556 |
| Installation | Drop-in with anti-walk pins |
| Weight | 3.2 oz |
| Dimensions | 2.5″ x 1.1″ x 0.6″ |
| Country of Origin | USA |
| Condition | New |
| SKU | FRT-MR3-FLAT |
Key Features
- Single-stage forced reset mechanism for rapid fire control
- 3-position selector compatibility (includes A1 and A4 drums)
- Tool steel construction with black oxide finish
- Includes anti-walk pins and installation screws
- Precision CNC machining for consistent performance
Who Should Buy This Trigger
Buy it if:
- You run an HK MR223/MR556 platform and want enhanced trigger performance
- You understand forced reset trigger mechanics and legal implications
- You demand precision machining in your firearm components
- You prefer US-made parts with proper hardening
Skip it if:
- You need a traditional two-stage trigger (see our standard triggers)
- Your jurisdiction restricts forced reset triggers
- You’re looking for budget components (this is a professional-grade part)
FRT-MR3 Pros & Cons
✅ Pros:
- Exceptional reset speed for rapid follow-up shots
- Includes both A1 and A4 selector drums for configuration flexibility
- Anti-walk pin system prevents trigger group movement
- Precision CNC machining ensures consistent performance
- Black oxide finish provides corrosion resistance
❌ Cons:
- Higher price point than standard triggers
- Requires understanding of forced reset mechanics
- Not compatible with all HK platforms (MR223/MR556 specific)
How It Compares
| Feature | FRT-MR3 (FLAT) | Budget Import Trigger | Premium Brand Trigger |
|---|---|---|---|
| Material | Tool steel | MIM steel | Billet aluminum |
| Hardness | 50-52 HRC | 40-45 HRC | 48-50 HRC |
| Compatibility | HK MR223/MR556 | Generic AR | Multiple platforms |
| Shipping | Same-day (USA) | 2-4 weeks | 3-5 days |
| Lifespan | 50,000+ rounds | 10,000 rounds | 30,000 rounds |
| Price | $603.75 | $60-80 | $250+ |
FRT-MR3 FAQ
Is the FRT-MR3 legal in my state?
Laws vary by jurisdiction. Consult local regulations before purchasing forced reset triggers.
What’s included in the package?
Trigger, 2 anti-walk pins, 4 screws, A1/A4 selector drums.
How difficult is installation?
Drop-in installation with basic tools. Anti-walk pins prevent movement.
What’s the pull weight?
Single-stage design with consistent pull throughout travel.
Where can I buy forced reset triggers online?
Available at F1Firearms (f1firearms.us.com) with same-day shipping.
Is this compatible with HK416?
No, specifically designed for MR223/MR556 platforms.
What’s the expected lifespan?
50,000+ rounds with proper maintenance.
✅ Same-day shipping from Topeka, KS
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
Browse more: Triggers | Full Shop
Field tested by Blake Hensley using HK MR556 platform. 500-round evaluation with no failures. Measurements verified with digital calipers. Last updated: May 2026
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