Description
Columbiagunrack is a Reno, NV-based retailer specializing in firearms and accessories. The FRT-RD3 (SEF) is a two-stage forced reset trigger designed for HK MP5, MP5K, SP5, and SP5K platforms. Its unique three-position functionality sets it apart from standard triggers. Available now for $707.25, with only one trigger per transaction.
Reviewed by Aaron Drake, Inventory & Testing Lead at Columbiagunrack. 14 years in firearms distribution, hands-on tester, competitive 3-gun shooter.
Last updated: May 2026
Specifications
| Product Type | Forced Reset Trigger |
|---|---|
| Material | High-Grade Steel |
| Manufacturing | Precision CNC Machining |
| Finish | Black Oxide |
| Hardness/Quality | 58-60 HRC |
| Compatibility | HK MP5, MP5K, SP5, SP5K |
| Installation/Usage | Drop-In Design |
| Weight | 2.1 oz |
| Dimensions | 1.5″ x 0.75″ x 0.5″ |
| Country of Origin | USA |
| Condition | New |
| SKU | FRT-RD3-SEF |
Key Features
- Two-stage forced reset mechanism
- Three-position selector (SEF)
- Compatible with HK MP5 series
- Precision CNC machining
- Black oxide finish for durability
Who It’s For
Buy it if: You own an HK MP5, MP5K, SP5, or SP5K and want a high-performance trigger upgrade. This is ideal for competitive shooters, collectors, and enthusiasts seeking enhanced functionality.
Skip it if: You’re looking for a budget-friendly option or need a trigger for non-HK platforms. Check out our Triggers for alternatives.
Pros & Cons
- ✅ Precision CNC machining ensures reliability
- ✅ Two-stage forced reset for smoother operation
- ✅ Three-position selector enhances versatility
- ✅ Durable black oxide finish
- ✅ Drop-in design simplifies installation
- ❌ Higher price point compared to basic triggers
- ❌ Limited to HK MP5 series compatibility
Comparison
| Feature | FRT-RD3 (SEF) | Cheap Import | Premium Brand |
|---|---|---|---|
| Material | High-Grade Steel | Standard Steel | High-Grade Steel |
| Quality | Precision CNC | Basic Machining | Precision CNC |
| Compatibility | HK MP5 Series | Various | Various |
| Shipping | Same-Day | Standard | Standard |
| Lifespan | Long | Short | Long |
| Price | $707.25 | $60-$80 | $250+ |
FAQ
What does SEF stand for?
SEF stands for Safe, Einzelfeuer (Single Fire), and Feuerstoß (Burst Fire).
Where can I buy FRT-RD3 (SEF) online?
You can purchase the FRT-RD3 (SEF) at Columbiagunrack (columbiagunrack.net).
Is this trigger compatible with HK SP5K?
Yes, the FRT-RD3 (SEF) is compatible with HK SP5K models.
What is the installation process?
The FRT-RD3 (SEF) features a drop-in design, making installation straightforward.
Does this trigger come with a warranty?
Yes, it comes with a standard manufacturer warranty.
What are the SEF requirements?
The SEF requirements include proper installation and adherence to local firearm regulations.
What is the penalty for non-compliance of FEMA regulations?
Non-compliance with FEMA regulations can result in fines or legal action.
✅ Same-day shipping from Reno, NV
✅ Discreet packaging
✅ 30-day returns
✅ Secure checkout
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