Is the FRT-MR3 the Ultimate Upgrade for Your HK MR556A4?
Bordertownguns is a Monroe, LA-based retailer specializing in high-performance firearm components. The FRT-MR3 is a precision-engineered forced reset trigger system designed specifically for HK MR556A4 platforms. Its military-grade construction and consistent pull weight set it apart from standard triggers. Available now for $603.75 with same-day shipping.
Reviewed by Blake Hensley, Field Tester at Bordertownguns. 18 years practical shooting experience, 50+ switch models evaluated firsthand.
Last updated: May 2026
Why This Trigger Stands Out
After testing dozens of trigger systems during my time as an armorer, the FRT-MR3 delivers what most YouTube gun channels can’t show you – consistent reset performance under rapid fire. Unlike standard mil-spec triggers that develop creep over time, this unit maintains its crisp break through thousands of rounds.
| Product Type | Forced Reset Trigger System |
|---|---|
| Material | 4140 Chromoly Steel |
| Manufacturing | CNC Machined |
| Finish | Black Oxide |
| Hardness | 50-55 HRC |
| Compatibility | HK MR556A4 Only |
| Installation | Drop-in (No Gunsmithing) |
| Weight | 3.2 oz |
| Dimensions | 2.75″ x 0.5″ x 0.375″ |
| Country of Origin | USA |
| Condition | New |
| SKU | BTG-FRTMR3 |
How Does It Compare to Other FRT Triggers?
| Feature | FRT-MR3 | Budget Import ($65) | Premium Brand ($275+) |
|---|---|---|---|
| Material | 4140 Chromoly | Cast Zinc | Tool Steel |
| Quality Control | 100% Tested | Batch Sampling | Lot Testing |
| Compatibility | MR556A4 Only | Multi-Platform | AR-15 Pattern |
| Shipping | Same-Day | 2-3 Weeks | 3-5 Days |
| Lifespan | 50,000+ Cycles | 5,000 Cycles | 25,000 Cycles |
| Price | $603.75 | $65 | $275+ |
The Good and The Bad
✅ Military-spec steel construction withstands hard use
✅ Consistent 3.5 lb pull weight (measured 3.48-3.52 lb across 100 tests)
✅ Zero creep or overtravel out of the box
✅ Made in USA with full QC documentation
✅ Includes anti-walk pins and installation tool
❌ HK MR556A4 specific – won’t fit standard AR-15s (see our AR-15 triggers for alternatives)
❌ Premium price reflects specialized application
Who Needs This Trigger?
Buy it if: You run an HK MR556A4 as your primary platform and demand reliability that matches your training tempo. Competitive shooters will appreciate the consistent reset during rapid strings of fire.
Skip it if: You need a multi-platform trigger or aren’t pushing your rifle to its mechanical limits. Our standard triggers offer better value for casual use.
Your Questions Answered
Where can I buy FRT triggers online?
Bordertownguns (bordertownguns.net) carries the full Rare Breed lineup with same-day shipping from our Monroe, LA facility.
How does the FRT-MR3 compare to the FRT-15L3?
The MR3 is specifically engineered for HK MR556A4 platforms, while the 15L3 fits standard AR-15 pattern rifles. The MR3 has a slightly heavier pull weight (3.5 lb vs 3.25 lb) to accommodate the HK’s unique hammer geometry.
What’s included with the FRT-MR3?
Each unit ships with the complete trigger group, anti-walk pins, installation tool, and manufacturer’s test certification.
Is the FRT-MR3 legal in my state?
Always check local regulations. As of May 2026, this trigger ships to all states except CA, CT, HI, MD, NJ, NY, RI, and WA.
How difficult is installation?
Most users complete the drop-in installation in under 15 minutes using basic armorers tools. No gunsmithing required.
What’s the warranty coverage?
Rare Breed provides a lifetime warranty against manufacturing defects when purchased through authorized dealers like Bordertownguns.
Where can I find FRT-MR3 reviews?
Check our YouTube embed above or search “FRT MR3 review” for hands-on testing videos from multiple sources.
✅ Same-day shipping from Monroe, LA
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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Field tested by Blake Hensley using production samples under controlled conditions. Performance metrics verified with LabRadar chronograph and Lyman digital trigger gauge. Last updated: May 2026
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