In conversations with a friend, there seemed to be some confusion amongst us, as to whether all Sig rails fit all modern rail mount lights. Of interest to me is whether a rail on a P226 Nitron finish circa 2017 would accommodate all of the modern lights from Streamlight and SureFire, or if there is a certain specification that I'd need to match to put a rail mount light/laser on a P226 like that.

In other words, is there something proprietary here that only allows Sig lights? ...or maybe it limits to only a certain spec of light type?

Pics of the example rail in question --

This message has been edited. Last edited by: r0gue,

From what I can gather, most lights/accessories for a 1913 rail should work.

For a SIG rail (what you have pictured), I’ve only ever mounted a Surefire light once or twice. For certain lights, such as their X300, Surefire makes two separate models, with the distinction being in the interface. Basically, one model is intended for metal frames and the other is intended for polymer frames. For classic metal-framed P-series pistols, most people (myself included) seem to have better luck with the version intended for metal frames.

I don’t know if other manufacturers make such distinctions as well, but I wouldn’t be surprised.

You don't need an X-300B for that rail, though you could use that version. An X-300A will work. You just need to use the correct key from those provided with these lights. In this case, the key marked "P" (for Picatinny) as I recall is what is required.

The gen5 Glocks use the same key, as opposed to earlier generation Glocks, which use the "UNIV-1" IIRC.

To be sure, a quick call to Surefire and/or Streamlight will clarify the matter.

To be clear, no, this is not a proprietary rail oN the SIG.

The Streamlight site seems to conflict. The TLR-7, TLR-8 Fitment Guide Found Here does not indicate compatibility. But the Interactive Webguide will take you to the TLR-8 if you take the P226 branch, -and/or- if you take the MK25 branch.

ChatGPT indicates that Streamlights sources of “fit” info doesn’t always agree.

PDF Fitment Guide (2025 revision):
This is the official engineering-style document. It’s conservative: if Streamlight hasn’t tested a perfect lockup on a frame, they leave it off. That’s why the rounded SIG rails aren’t listed there — too much variation and risk of cosmetic or fit issues.

Interactive Web Guide:
This tool is more sales-facing. It often sends you to a “recommended” light (like the TLR-8) for a given pistol family, even if the fit may not be 100% ideal. That’s why both the P226 (SIG Rail) and MK25 (1913 rail) branches funnel to the TLR-8 — it’s essentially saying, “this is the light we’d suggest for a P226 series pistol,” but it doesn’t distinguish carefully between rail generations.

The web tool is optimized to recommend a product, while the PDF is the hardline compatibility chart.

This message has been edited. Last edited by: r0gue,

My TLR-8 came with a Sig key for the light.
It came with ones for just about every pistol out there.
The one I used is the UNIV-1

quote:

Originally posted by powermad:
My TLR-8 came with a Sig key for the light.
It came with ones for just about every pistol out there.
The one I used is the UNIV-1

Ahhhh, so it comes with all of the various keys!? I was reading some chart somewhere and I interpreted that there were separate SKUs for each, so I thought I had to predetermine.

So the fit is good for you on a SIG Rail? What model Sig pistol? Did you get the compact one (HL-X SUB)?, or did you go with the normal size (HL-X)?

Thanks powermed!

I got the TLR-8 when it first came out.
It works on all of my Sigs with the curved Sig rail.

Incoming! I'll let you know how it turns out.

Streamlight 69434 TLR-8A G Flex 500-Lumen Low Profile Pistol Light with Integrated Green Aiming Laser