Considering the Tango Fire 4000?
Don’t buy it. It has no built-in environmental sensors and it’s outranged by a $130 handheld Sig Sauer rangefinder. It also suffers the same wide, diagonal beam divergence problem as the Vortex Impact 4000, so you’ll have trouble ranging cleanly around brush, trees and other clutter near the target. On top of that it has a firmware bug that silently stops updating your ballistic dope mid-string, plus a separate bug that uses the tilt of your phone instead of the rifle for slope calculations. None of these issues have been fixed or even acknowledged by the Chinese company behind it, its ballistic software is being pushed toward a cloud-only app, and by multiple accounts its customer support amounts to gaslighting customers rather than helping them.
Instead of a Tango Fire 4000, you need the product pictured below, and this blog article is going to explain why:
How does the $1,500 Tango Fire 4000 WMLRF compare to a much less expensive Sightlok RF-1 + Sig Sauer rangefinder combo? For this comparison, we selected the Sig Sauer KILO2200 BDX rangefinder, which sells for $130 on Amazon, because it offers the equivalent ranging performance of the Tango Fire 4000 WMLRF. Let’s step through the issues, in order of importance.
1. Built-in Environmental Sensors — Sightlok RF-1 / Sig Sauer WINNER
The Tango Fire 4000 has been widely criticized for lacking the built-in environmental sensors needed for accurate ballistic calculations. On the Tangoinnos website, the company repeatedly implies they aren’t even sure why the Chinese engineers left them out. In a section entitled “Why does the FIRE4000 lack environmental sensors on board?” they write:
Later, in the same FAQ, they again write:
While the low-end Sig KILO2200 doesn’t come with built-in environmental sensors either, Sig Sauer offers a full suite of them on their KILO2400ABS, KILO4K, KILO5K, and KILO8K-ABS models — and even the KILO8K-ABS, which puts the Tango Fire 4000 to shame, costs $200 less. With the Tango Fire 4000, you’re paying for the box, not the rangefinder itself.
2. Ranging Performance and Price — Sightlok RF-1 / Sig Sauer KILO2200 WINNER
Wildly optimistic range estimates from the manufacturer notwithstanding, in real-world ranging, the $130 Sig Sauer KILO2200 outperforms the $1,500 Tango Fire 4000:
Ranging trees: Sig Sauer 1,600 yards, Tango Fire 4000 1,500 yards
Ranging animals (Deer/Elk): Sig Sauer 1,300 yards, Tango Fire 4000 1,200 yards
You’re paying $1,500 for a product that is functionally inferior to a low-end $130 Sig Sauer rangefinder. You might think of the Tango Fire 4000 as a $100 rangefinder in a $1,400 box.
The price gap compounds the problem. The Sightlok-Sig combo costs a combined $379, versus $1,500 for the Tango Fire 4000 — choosing Sightlok and Sig saves you more than $1,100, or 75%.
3. Beam Divergence — Sightlok RF-1 / Sig Sauer WINNER
Tango Innovations doesn’t publish a beam divergence spec for the Fire 4000, but field reports describe the same failure mode that plagues the Vortex Impact 4000: a wide, angled beam that catches branches, grass, and terrain alongside the actual target instead of isolating it. On the Impact 4000, Vortex’s own published figures put that beam divergence at 2.0 x 0.2 MRAD at a 45° angle — a “slash-shaped” beam that’s ten times larger on its wide axis than its narrow axis, and 67% wider than the rectangular beam on a comparable Sig KILO8K. The Tango Fire 4000 shows the same real-world symptoms in the field, which points to the same underlying beam-shape problem.
Want a Rangefinder That Actually Reads Through Brush?
The Sightlok RF-1 mount turns a handheld Sig Sauer rangefinder — with a narrower, cleaner beam than the Tango Fire 4000 — into a weapon-mounted rangefinder that co-witnesses with your scope.
4. Continuous Ranging Bug — Sightlok RF-1 / Sig Sauer WINNER
First reported on Snipershide, if you engage continuous ranging by “long pressing” the remote or onboard range button, after 2-3 consecutive ranges the unit will continue ranging but stop updating the dope. Rangefinding continues to work, but firing solutions no longer update — with no warning. That could lead to shots being taken with wildly inaccurate dope.
5. Inclinometer Bug — Sightlok RF-1 / Sig Sauer WINNER
Users have also reported that when the BOSS phone app is connected to the Tango Fire 4000, the dope calculations stop using the angle of the rangefinder and start using the angle of the mobile phone instead. Rather than conceding there’s a bug, the Tangoinnos rep posted this response:
6. Company Responsiveness — Sightlok RF-1 / Sig Sauer WINNER
It’s been months since the continuous ranging bug was first reported. The TANGOINNOS rep Mfelici1!! is following the thread, but there’s been no meaningful response. This is a dangerous product flaw that merits a much different stance from the company — perhaps even a recall — and yet the company has been largely silent. A respected vendor like Sig Sauer would at least acknowledge the problem and announce plans for a fix.
7. Ballistic Software — Sightlok RF-1 / Sig Sauer WINNER
While both Sig Sauer and the Tango Fire 4000 utilize Applied Ballistics software, the applications are different. Sig Sauer uses BDX, while the Tango uses the “AB Synapse – BOSS” app. That app is no longer in development, and users are being shifted to Applied Ballistics Quantum — a cloud-based app. Do you really want your ballistic calculator depending on a cloud app? An app that poses obvious privacy concerns. Plus now, when you’re out in the field without an internet connection, you can’t grab drag curves or bullet data that isn’t already cached locally on your device. To the best of our knowledge, Sig Sauer BDX continues to be developed and supported.
8. Customer Support — Sightlok RF-1 / Sig Sauer WINNER
Just in reference to the electro-optics portion, you will receive radically better after-sales support from Sig Sauer than you will from Tango Innovations Inc. Sig Sauer rangefinders are covered by the SIG SAUER Electro-Optics Infinite Guarantee™, a fully transferable, lifetime warranty for both structural and electronic components. Compare that to Tango Innovations, where you’re dealing essentially with the U.S. branch of a Chinese company.
And this isn’t just an allegation — it’s documented in customer comments both on Snipershide and right here on our own site. One commenter wrote: “I’ve been texting back and forth with Marcus with the Tangoinnos company… after reading this blog post I realize I’ve been gaslit.” Another reported: “I am having trouble with the 4000 it won’t hold zero and I have to constantly readjust it… I have a call in, it’s been one day and no response yet.” Sniper’s Hide reports are similar — one long-time member who had bad things to say about the Fire 4000 reportedly had his account deleted.
As far as after-sales support goes with Sightlok, like Sig, we have an iron-clad guarantee on our product and we are an American company with American customer support agents and American engineering experts on hand to support our customers. We have also yet to receive a return of a Sightlok RF-1, which speaks to its durability.
Conclusion — Sightlok RF-1 / Sig Sauer KILO2200 WINNER
The majority of shooters can achieve better overall rangefinding performance, at a fraction of the cost, with none of the bugs or support headaches, by choosing a Sightlok RF-1 and Sig Sauer rangefinder combination over the Tango Fire 4000.
Build a Better WMLRF Than the Tango Fire 4000
- Outranges the Tango Fire 4000 for a fraction of the price — $379 combined vs. $1,500
- Backed by Sig Sauer’s Infinite Guarantee™, not an unresponsive overseas support team
- No firmware bugs silently killing your dope or misreading your rifle’s angle
- Optional built-in environmental sensors on mid- and higher-end Sig rangefinders
- Narrower, cleaner beam that reads through brush instead of catching it
Have a different opinion? Find any errors in our report? Please share your opinion below!
