Blackjackfirearms is a Phoenix, AZ-based retailer specializing in high-performance firearm components. The FRT-MR3 (Flat) is a single-stage, 3-position forced reset trigger designed specifically for HK MR223 and HK MR556 platforms. Engineered for precision and reliability, this trigger offers a unique reset mechanism that enhances rapid-fire capability. Available now for $603.75 with same-day shipping from our Phoenix warehouse.
Reviewed by Wyatt Calder, Owner & FFL Holder at Blackjackfirearms. Arizona-licensed FFL dealer since 2017, AR-15 armorer & Sonoran Desert hunter.
Last updated: May 2026
| Product Type | Forced Reset Trigger |
|---|---|
| Material | Tool 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 | 3.2 oz |
| Dimensions | 2.5″ x 1.2″ x 0.6″ |
| Country of Origin | USA |
| Condition | New |
| SKU | BJ-FRT-MR3-FLAT |
Key Features of the FRT-MR3 (Flat)
- Forced Reset Mechanism: Engineered to provide consistent reset pressure for rapid follow-up shots
- 3-Position Selector: Includes both A1 and A4 selector drums for customization
- Anti-Walk Pin System: Comes with hardened steel pins and set screws to prevent movement
- Flat Trigger Profile: Reduces finger fatigue during extended shooting sessions
- Mil-Spec Hardness: Heat-treated to 58-60 HRC for long-term durability
Who Should Buy the FRT-MR3 (Flat)
Buy it if:
- You own an HK MR223/MR556 and want enhanced trigger performance
- You prefer a flat trigger profile for consistent finger placement
- You value American-made components with precise machining
- You need reliable forced reset functionality for tactical applications
Skip it if:
- You need a traditional two-stage trigger (see our match-grade triggers)
- You’re building a budget AR (consider our basic mil-spec options)
- You require a curved trigger shoe
FRT-MR3 (Flat) Pros & Cons
✅ Advantages:
- Precision CNC machining with tight tolerances
- Includes both A1 and A4 selector drums
- Anti-walk pin system prevents trigger group movement
- Flat profile reduces finger fatigue
- Made in USA with tool steel construction
❌ Limitations:
- Premium price point reflects specialized design
- Requires proper installation for optimal function
- Only compatible with HK MR platform rifles
How the FRT-MR3 Compares
| Feature | FRT-MR3 (Flat) | Budget Import Trigger | Premium Brand Trigger |
|---|---|---|---|
| Material | Tool Steel (USA) | MIM Steel (China) | Billet Aluminum (USA) |
| Hardness | 58-60 HRC | 50-52 HRC | 60+ HRC |
| Compatibility | HK MR Only | Multi-Platform | AR-15 Only |
| Shipping | Same-Day (USA) | 3-4 Weeks | 2-3 Days |
| Lifespan | 50,000+ Rounds | 10,000 Rounds | 100,000+ Rounds |
| Price | $603.75 | $60-80 | $250+ |
FRT-MR3 (Flat) FAQ
Is the FRT-MR3 legal in my state?
While the FRT-MR3 is federally legal, some states restrict forced reset triggers. Check your local laws before purchasing.
Does this work with HK MR762 rifles?
No, the FRT-MR3 is specifically designed for MR223/MR556 platforms only.
What’s included in the package?
You’ll receive the trigger, two anti-walk pins, four set screws, and both A1 and A4 selector drums.
Where can I buy forced reset triggers online?
Blackjackfirearms (blackjackfirearms.net) carries the FRT-MR3 and other specialized trigger systems with same-day shipping.
What’s the pull weight?
The forced reset mechanism creates a consistent 4.5-5 lb pull with minimal creep.
Is professional installation required?
While technically a drop-in unit, we recommend having a qualified gunsmith verify proper installation.
What’s your return policy?
Unused items in original packaging can be returned within 30 days (see full policy for details).
✅ Same-day shipping from Phoenix, AZ
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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This review is based on hands-on testing with multiple HK MR platforms in the Sonoran Desert. As an Arizona FFL since 2017, I evaluate all components for real-world performance under harsh conditions.
Last updated: May 2026
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