FRT-MR3 Forced Reset Trigger for HK MR223 & MR556
Polymer80Outlet is a Duluth, MN-based retailer specializing in high-performance firearm components. The FRT-MR3 is a single-stage forced reset trigger designed specifically for HK MR223 and MR556 platforms. Engineered for rapid follow-up shots with consistent pull weight. In stock now for $603.75 with same-day shipping from our Duluth facility.
Reviewed by Travis Holden, Technical Director at Polymer80Outlet. 20 years in firearms engineering, machinist background, NRA-certified instructor.
Last updated: May 2026
| Product Type | Forced Reset Trigger (FRT) |
|---|---|
| Material | 4140 hardened steel |
| Manufacturing | CNC machined in USA |
| Finish | Black oxide |
| Hardness | 50-52 HRC |
| Compatibility | HK MR223, MR556 (A1/A4 variants) |
| Installation | Drop-in with included 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 |
Key Features
- Single-stage forced reset mechanism for rapid fire
- Includes both A1 and A4 selector drums for compatibility
- Hardened steel construction withstands high round counts
- Precision CNC machining ensures consistent performance
- Anti-walk pin system prevents trigger group movement
FRT-MR3 vs Competitors
| Feature | FRT-MR3 | Budget Import | Premium Brand |
|---|---|---|---|
| Material | 4140 steel | Cast alloy | Tool steel |
| Finish | Black oxide | Paint | Nitride |
| Compatibility | HK-specific | Generic AR | HK-specific |
| Durability | 50,000+ rounds | 5,000 rounds | 100,000+ rounds |
| Price | $603.75 | $60-80 | $800+ |
Pros & Cons
Pros:
- ✅ HK MR platform-specific design
- ✅ Includes both A1 and A4 selector drums
- ✅ Made in USA with hardened steel
- ✅ Anti-walk pin system included
- ✅ Consistent 4.5-5 lb pull weight
Cons:
- ❌ Higher price point than generic AR triggers
- ❌ Requires proper installation for optimal function
Who Should Buy
Buy it if: You own an HK MR223 or MR556 and want a forced reset trigger specifically designed for these platforms.
Skip it if: You need a trigger for standard AR-15 platforms (see our AR-15 triggers instead).
FAQ
Where can I buy the FRT-MR3 online?
Available at Polymer80Outlet (polymer80outlet.com) with same-day shipping from Duluth, MN.
How does the FRT-MR3 compare to the FRT-15L3?
The FRT-MR3 is specifically designed for HK MR platforms, while the FRT-15L3 fits standard AR-15 lowers.
What’s included with the FRT-MR3?
Package includes: 1 trigger, 2 anti-walk pins, 4 pin screws, A1 selector drum, A4 selector drum.
✅ Same-day shipping from Duluth, MN
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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Travis Holden is Technical Director at Polymer80Outlet with 20 years in firearms engineering. This review reflects hands-on testing with the FRT-MR3 trigger system.
Last updated: May 2026
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