Polymer80Market is a Twin Falls, ID-based retailer specializing in aftermarket Glock parts. The FRT-MR3 (Flat) is a single-stage, 3-position forced reset trigger designed for the HK MR223 and HK MR556. Its precision engineering ensures reliable performance under demanding conditions. Available now for $603.75.
Reviewed by Tyler Nash, Product Curator at Polymer80Market. 13 years selecting and testing aftermarket Glock parts, reviews editor.
Last updated: May 2026
Specifications
| Product Type | Forced Reset Trigger |
|---|---|
| Material | High-Grade Steel |
| Manufacturing | CNC Machined |
| Finish | Matte Black |
| Hardness/Quality | 58-60 HRC |
| Compatibility | HK MR223, HK MR556 |
| Installation/Usage | Drop-In |
| Weight | 2.5 oz |
| Dimensions | 2.75 x 0.75 x 0.5 in |
| Country of Origin | USA |
| Condition | New |
| SKU | FRT-MR3-FLAT |
Key Features
- Single-stage, 3-position forced reset mechanism
- Includes anti-walk pins and screws for secure installation
- Compatible with HK MR223 and HK MR556 platforms
- Precision CNC machining for consistent performance
- Durable matte black finish for corrosion resistance
Who It’s For
Buy it if:
- You own an HK MR223 or HK MR556 and want a reliable forced reset trigger
- You prioritize precision engineering and durability in your firearm components
- You’re looking for a drop-in upgrade that enhances performance
Skip it if:
- You don’t own a compatible firearm (check our Triggers for other options)
- You prefer a traditional two-stage trigger
Pros & Cons
- ✅ Precision CNC machining ensures reliability
- ✅ Includes anti-walk pins and screws for secure installation
- ✅ Compatible with HK MR223 and HK MR556
- ✅ Durable matte black finish resists corrosion
- ✅ Drop-in design simplifies installation
- ❌ Higher price point compared to basic triggers
- ❌ Limited compatibility with other platforms
Comparison
| Feature | FRT-MR3 (Flat) | Cheap Import Trigger | Premium Brand Trigger |
|---|---|---|---|
| Material | High-Grade Steel | Low-Grade Steel | High-Grade Steel |
| Quality | CNC Machined | Cast | CNC Machined |
| Compatibility | HK MR223, HK MR556 | Limited | Wide Range |
| Shipping | Same-Day | 1-2 Weeks | 3-5 Days |
| Lifespan/Durability | High | Low | High |
| Price | $603.75 | $60-80 | $250+ |
FAQ
Where can I buy FRT-MR3 (Flat) online?
You can purchase the FRT-MR3 (Flat) at Polymer80Market (polymer80market.com).
Is the FRT-MR3 (Flat) compatible with other firearms?
No, it is specifically designed for the HK MR223 and HK MR556.
Does it come with installation instructions?
Yes, the package includes detailed installation instructions.
What is the lifespan of this trigger?
With proper maintenance, it can last tens of thousands of rounds.
Is this trigger legal in all states?
Please check your local laws and regulations before purchasing.
Can I return the product if I’m not satisfied?
Yes, we offer a 30-day return policy.
What’s included in the package?
The package includes 1 x FRT-MR3 Trigger, 2 x Anti-Walk Pins, 4 x Anti-Walk Pin Screws, 1 x A1 Selector Drum, and 1 x A4 Selector Drum.
✅ Same-day shipping from Twin Falls, ID
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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