How to Mount the TLR-7 HL-X Sub Closer to the Trigger on Staccato C3.6
Jason PineShare
By Jason Pine — Four Brothers Holsters, Logansport, IN
We love small engineering wins that make a big practical difference. When working with the Staccato HD C3.6 and the Streamlight TLR-7 HL-X Sub (1913/rail version), we noticed the light sat a hair farther forward than we'd like on the pistol’s accessory rail. That small gap can translate to a less-than-ideal profile and a light that doesn’t sit as close to the trigger guard as the shooter (or the holster) would prefer.
To solve it, we designed a precision key that moves the TLR-7 HL-X Sub as close to the trigger guard as safely possible, improving concealment, holster fit, and the overall feel of the pistol/light interface without modifying the firearm or light.
Here’s the story: the constraints, the process, and why we think this is a small part that pays big dividends.
Why Does Weapon Light Placement Matter for Concealed Carry?
- Bringing the light closer to the trigger guard shortens the overall profile and reduces muzzle-forward overhang, which is important for concealment and drawing from our holster.
- A tighter light-to-rail fit reduces the distance from the hand to the light switches.
- It lets us design holsters that rely on a consistent light placement so retention and clearance are predictable.
What Were the Design Requirements for the Staccato C3.6 Light Key?
From the outset, we set a few nonnegotiables:
- No permanent modification to the pistol or the Streamlight light.
- Maintain full function of the light and safe clearance from the trigger guard and controls.
- Simple, repeatable install for the end user with common hand tools.
- Durable—able to hold position under recoil and repeated holstering cycles.
How Did Four Brothers Holsters Engineer the TLR-7 Sub Rail Key?
1. Measurement and baseline fit checks. We carefully measured the Staccato rail interface, the TLR-7 Sub mounting footprint, and the clearance to the trigger guard. This established the maximum safe offset we could achieve without interfering with controls or the shooter’s finger position.
2. CAD modeling. Using parametric CAD, we modeled variants of the key with incremental offsets and engagement points. That allowed us to quickly iterate on how the key contacts both the rail and the light while maintaining positive retention.
3. Prototyping. For first passes, we 3D printed prototypes in resilient plastics to verify fit, reach, and alignment. These quick iterations allowed us to catch interference issues early and validate that bringing the light back would not contact the trigger guard under normal handling.
4. Material selection. After prototyping, we moved to a production material that balances stiffness and shock resistance. The final key is built from a durable engineering polymer with a tight tolerance finish to keep the light from shifting during use.
5. Safety and tolerance testing. We tested holstering/drawing cycles, dry-firing compatibility checks (without live ammo for safety verification), and stress tests to ensure the key stayed secure through heavy use.
How Do You Install the Staccato C3.6 Light Key?
Installation is simple and reversible. All that is needed is to remove the factory key included with the 1913 TLR-7 Sub light and replace it with our key. It will only go in the light one way, making it easy to add. Our key will engage two slots on the Staccato C3.6 pistol. Be sure to snug the light on the pistol until it is securely attached.
What Performance Improvements Does the Light Key Provide?
After testing the key on multiple C3.6 examples and with the Streamlight TLR-7 HL-X Sub (Streamlight model 69505), we observed a decrease in the gap between the trigger guard and the light and easier access to the light switches with a full grip on the pistol.
Where to Get the Key and the Light
If you want one for your Staccato HD C3.6, check out the Staccato HD C3.6 Streamlight TLR-7 Sub Key we engineered. We recommend pairing it with the Streamlight TLR-7 HL-X Sub (our preferred light) — Streamlight model 69505.
Want holsters that take advantage of the tighter light placement? Browse our full Staccato collection here.
Our Final Thoughts
This key is a small, reversible, field-serviceable part that lets shooters get the most out of the Staccato HD C3.6 + TLR-7 HL-X Sub combination without altering the pistol or the light. It’s exactly the kind of problem we love: practical manufacturing and fitment engineering that enhances performance and the end-user experience.
Questions or feedback? If you’ve mounted the kit and want to give us feedback, reply to this post or email us at team@fourbrothersinc.com. We’re always iterating.
FAQ
Q: Will this key work on other Staccato models?
A: The key was designed specifically for the HD C3.6 rail geometry. Other Staccato models may require different offsets—contact us if you want help with a different model.
Q: Will using the key void my warranty?
A: The key is a reversible accessory and does not modify the firearm or the light. However, we recommend checking any warranty terms from the pistol or light manufacturer before installation.
Q: Can I install this myself?
A: Absolutely. The kit ships with instructions and common tool installation steps. If you’re uncomfortable, reach out to us for help.
