Q: Tango Fire 4000 or Vortex Impact 4000: which is the better WMLRF?
A: Of the two dedicated units, the Tango Fire 4000. See why the Tango Fire 4000 beats the Vortex Impact 4000.
Q: What did you judge the Tango Fire 4000 and Vortex Impact 4000 on?
A: Eight criteria: beam divergence, real-world ranging distance, wired or Bluetooth remote, ballistic software, whether you can range without pointing your muzzle at the target, cold-weather reliability, company support and warranty, and total cost.
Q: Is there a third option besides the Tango Fire 4000 and the Vortex Impact 4000?
A: Yes, an increasingly popular solution to the “WMLRF problem” is mounting a handheld rangefinder to your rifle using a Sightlok RF-1 rangefinder mount.
The approach has some disadvantages. Overall, however, it’s a more flexible, modular, and cost-effective solution that, depending on the rangefinder you deploy, can actually deliver more accurate results in the field.
The finished setup looks like this:
The Sightlok RF-1 protects your rangefinder from recoil, bumps, and scratches. A polymer hood protects the rangefinder as a whole, and hard rubber covers protect the laser aperture and eyepiece.
Q: What are some advantages of the Sightlok RF-1 vs the Tango Fire 4000 and the Vortex Impact 4000?
A:
Quick Detach to range objects you don’t want to point your muzzle at
Keep rangefinder warm in your pocket until needed to avoid cold weather failures
Use superior handheld lasers with superior ballistic software
Roughly $1000 cheaper
Q: What about recoil? Can’t it damage my rangefinder?
A: Handheld rangefinders are designed to survive drops of about 3 feet, and the impact from a 3-foot drop can generate several thousand psi of pressure. The RF-1 spreads recoil so evenly that no spot on your rangefinder takes more pressure than your thumb puts on the range button, a few dozen psi at most. A few dozen psi is well under 1% of the pressure your rangefinder is built to survive in a 3-foot drop. At that margin, the chance of a .308 shot damaging a healthy rangefinder in the RF-1 is effectively zero. In two years of selling the Sightlok RF-1, no customer has reported a rangefinder damaged by recoil. Read our full analysis of the recoil question and watch recoil test videos.
What about recoil? Won’t my rangefinder be damaged if I mount it to my rifle?
To understand the probability of damage from recoil to your rangefinder, we must take into account how much force is being applied by common rifle cartridges like the .308, how that force is distributed, and roughly how close that comes to the amount of force necessary to actually damage your rangefinder.
How much force?
The amount of force is not that great. For example, in the case of a .308, the cumulative force of the recoil is about equal to the force of you picking up your rangefinder and squeezing it hard for a few thousandths of a second.
How is the force distributed?
Beyond the actual amount of force is an even more critical factor: How the force is distributed. The Sightlok RF-1 uses 3M impact-absorbing rubber to hold the rangefinder and evenly distribute the recoil forces while simultaneously shielding sensitive areas like the buttons, the laser aperture lenses, the ocular, and the ocular lenses from impact. Lastly, when the rangefinder is held in the RF-1 mount, recoil force travels straight back along the bore axis, rather than to corners or edges where impact forces can cause more damage. The result of these mitigating factors is that recoil generates about the same amount of pressure on your rangefinder as you exert when you press the range button.
Typical standards for rangefinder durability
Handheld rangefinders are designed to survive drops of about 3 feet, and the impact from a 3-foot drop can generate several thousand psi of pressure.
How close does recoil come to causing damage?
The RF-1 spreads recoil so evenly that no spot on your rangefinder takes more pressure than your thumb puts on the range button, a few dozen psi at most. A few dozen psi is well under 1% of the pressure your rangefinder is built to survive in a 3-foot drop. At that margin, the chance of a .308 shot damaging a healthy rangefinder in the RF-1 is effectively zero.
No reported failures
In two years of selling the Sightlok RF-1, no customer has reported a rangefinder damaged by recoil.
Recoil tests on video
Below, a US military rifleman tests the Sightlok RF-1 with recoil from two common cartridges.
Sig Sauer KILO1000BDX versus .308 rifle recoil:
Sig Sauer KILO1000BDX versus 6.5 Creedmoor rifle recoil:
Q: What about the rangefinder remote? Don’t I lose that feature with the Sightlok RF-1?
A: Yes, you do lose that feature. The Tango Fire 4000 has a wired remote, and the Vortex Impact 4000 has a Bluetooth remote. A Sightlok RF-1 setup typically does not have either (unless you are using a rangefinder with a wired remote like the LE032). This means rather than triggering your rangefinder with your right hand by pressing a remote switch near the trigger, you typically mount your rangefinder on the left or top of your scope, and press the range button with your left hand while holding your rifle with your right. This works fine if you shoot off a tripod, bipod, bag, etc., but it’s a disadvantage if you shoot with nothing to support your rifle except your left arm. The Vortex Impact 4000’s Bluetooth remote has its own problems, which we describe in the Vortex Impact 4000 section.
Q: What about weight? Does the Sightlok RF-1 solution weigh more?
A: Slightly more than the Tango Fire 4000 and the Vortex Impact 4000.
Weight Comparison – Tango vs Vortex vs Sightlok
| Part | Tango Fire 4000 | Vortex Impact 4000 | Sig KILO2200 + Sightlok RF-1 |
|---|---|---|---|
| Rangefinder | About 14.8 oz for the whole unit | 16 oz for the whole unit | Sig Sauer KILO2200: 7.5 oz |
| Rangefinder mount | Sightlok RF-1: 7 oz | ||
| Quick-detach kit | Not needed | Not needed | Sightlok QD accessory: about 0.9 oz |
| Protective cover | Not needed | Not needed | Sightlok polymer protective cover: about 2.6 oz |
| Total | ✅ About 14.8 oz | About 16 oz (1 lb) | About 18 oz |
| Difference | The Sig KILO2200 + Sightlok RF-1 weighs about 3.2 oz more than the Tango Fire 4000 and about 2 oz more than the Vortex Impact 4000 | ||
👉 Read on for the full comparison and the pros and cons of each option.
Or jump straight to an answer: What is the best WMLRF? · If I don’t already own a good handheld rangefinder, which one should I use with the Sightlok RF-1? · See all FAQs
Feature Comparison – Tango vs Vortex vs Sightlok
| Criterion | Tango Fire 4000 | Vortex Impact 4000 | Handheld + Sightlok RF-1 |
|---|---|---|---|
| Beam divergence | Beam divergence not published; field reports describe the same ranging symptoms as the Vortex Impact 4000 | Excessive beam divergence with a diagonal beam pattern, canted 45° | ✅ With a decent rangefinder like a Sig: a narrow, round or rectangular beam with low beam divergence |
| Real-world range | 1,500 yds trees / 1,200 yds animals | Can fail to range past 400 yds in brush | ✅ 1,600 yds trees / 1,300 yds animals (assuming $130 Sig KILO2200) |
| Wired or Bluetooth remote | ✅ Wired remote, instant | Bluetooth remote: battery drain or re-pairing delay | You press the rangefinder’s range button with your support hand |
| Ballistic software | Applied Ballistics, in an app Tango Innovations is moving to the cloud | GeoBallistics (proprietary) | ✅ Applied Ballistics on most decent handhelds |
| Range without pointing muzzle at target | No (integrated unit) | No (integrated unit) | ✅ Yes (you can quickly detach the RF-1 from the rail) |
| Cold weather | No major reports | Battery and display failures | ✅ Keep the handheld in your pocket between shots |
| Support and warranty | Poor, with documented complaints | Strong | ✅ Your handheld’s own warranty, plus US-based Sightlok support |
| Cost | $1,500 | $1,500 | ✅ $490 (Sig KILO2200, Sightlok RF-1, QD accessory and cover) |
Visual Proof of the Problem
This night vision photo shows the Vortex Impact 4000’s 45° slash beam pattern. Tango Innovations doesn’t publish a beam divergence figure for the Tango Fire 4000. The Tango Fire 4000 shows the same real-world symptoms in the field, and we think it may actually share the same laser unit that’s used by Vortex.
Numerical Proof of the Problem
Here’s how the Vortex Impact 4000’s beam divergence compares with three Sig handheld rangefinders:
| Rangefinder | Beam divergence | Beam pattern | Widest beam spread at 500 yards |
|---|---|---|---|
| Vortex Impact 4000 | 2.0 x 0.2 MRAD | “Slash-shaped,” canted 45° | 36 inches |
| Tango Fire 4000 | Not published | Field reports describe excessive beam divergence and a diagonal beam pattern | Not published |
| Sig KILO2200 | 1.4 MRAD | Round (30% narrower) | 25 inches |
| Sig KILO5K | 1.3 MRAD | Round (35% narrower) | 23 inches |
| Sig KILO8K-ABS | 1.2 x 0.25 MRAD | Rectangular, wider than tall (40% narrower) | 22 inches |
Result of the Problem
Due to the excessive beam divergence, the beam hits more branches, grass and ground around the target, resulting in more false or blended readings than you’d find with better quality, lower beam divergence rangefinders.
Tango Fire 4000
Pros
- Wired “rat’s tail” remote, for instant ranging
- All-in-one package, nothing to assemble or align
- Runs Applied Ballistics rather than a proprietary solver
- No widespread cold-weather failure reports
Cons
- No built-in environmental sensors
- Shorter real-world range than a $130 Sig KILO2200 handheld
- Field reports describe the same excessive beam divergence and diagonal beam pattern as the Vortex Impact 4000
- Two unfixed firmware bugs that can affect your firing solution
- Tango Innovations is moving the ballistic software to a cloud app. Depending on a cloud app means you need an internet connection to grab drag curves or new bullet data, often not practical when you’re out in the field.
- A company that doesn’t appear to support its product or its customers. We suspect Tango Innovations is basically the U.S. sales office for Henrich Technology, a Chinese company (see why)
The Tango Fire 4000’s wired remote is its biggest advantage vs the Vortex because a wired remote works every time and there’s never anything to wake up or reconnect.
The Tango Fire 4000 lacks environmental sensors, so you depend on your mobile phone or a Kestrel to get that data. Tango Innovations says it doesn’t know why the environmental sensors were left out of the Tango Fire 4000, suggesting that the product was not only manufactured, but designed in China, so the “Designed in U.S.” label is probably disingenuous.
The Tango Fire 4000’s firmware bugs are its most serious problem. If you hold the button for continuous ranging, after 2 to 3 ranges the unit can keep showing new ranges but stop updating your firing solution, with no warning. Separately, with the phone app connected, a firmware bug causes the Tango Fire 4000 ballistic calculator to use the angle you’re holding your phone, rather than the angle you’re holding your rifle, as the shooting angle. Tango Innovations hasn’t fixed either bug.
Read our full Tango Fire 4000 review here.
Vortex Impact 4000
Pros
- Onboard environmental sensors: compass, temperature, pressure, humidity
- Vortex’s VIP warranty, and Vortex support staff who answer the phone
- Well-built, and an all-in-one package
- Patented Wind Bearing Capture mode
Cons
- Excessive beam divergence and a 45° slash-shaped beam pattern
- Bluetooth remote: drains batteries when connected, slow to re-pair when switched off
- Battery and display failures in cold weather
- GeoBallistics instead of the industry-standard Applied Ballistics
- Compass calibration many owners can’t complete
- Night display that can’t be dimmed
The Vortex Impact 4000 ranks below the Tango Fire 4000 because of its Bluetooth remote. Leave the remote paired and you drain the batteries in both the remote and the rangefinder. Power the remote down and you have to re-pair it before every range.
The Vortex Impact 4000 has a record of cold-weather failures. Owners in multiple Snipershide threads report battery life dropping to as little as 15 minutes, and at the Mammoth Sniper Challenge nearly all of roughly 30 Impact 4000 shooters had failures or major ranging problems.
Read our full Vortex Impact 4000 review here.
Handheld Rangefinder + Sightlok RF-1
Pros
- With a decent handheld like a Sig KILO2200 or better: a narrow, round or rectangular beam with low beam divergence
- You can quickly detach the RF-1 from the rail when you want to range a target you don’t want to point your muzzle at, and reattach when you’re done, while maintaining an accurate co-witness between your rangefinder and scope
- Keep the rangefinder warm in your pocket between shots in the cold
- Longer real-world ranging distance with a decent handheld, even the Sig KILO2200
- Works with almost any handheld rangefinder, so you’re not locked into one brand
- Applied Ballistics on most decent handhelds, with onboard environmental sensors on Sig’s handhelds from the KILO3K up
- No bright display on the rifle giving away your position at night
- Your handheld’s own warranty, plus US-based Sightlok support
Cons
- No remote. You press the rangefinder’s own range button with your support hand, so you have to take that hand off the rifle
Price Comparison – Tango vs Vortex vs Sightlok
| Part | Tango Fire 4000 | Vortex Impact 4000 | Sig KILO2200 + Sightlok RF-1 |
|---|---|---|---|
| Rangefinder | $1,500 for the whole unit | $1,500 for the whole unit | Sig Sauer KILO2200: $130 |
| Rangefinder mount | Sightlok RF-1: $200 | ||
| Quick-detach kit | Not needed | Not needed | Sightlok QD accessory: $90 |
| Protective cover | Not needed | Not needed | Sightlok polymer protective cover: $70 |
| Total | $1,500 | $1,500 | ✅ $490 |
| Difference | The Sig KILO2200 + Sightlok RF-1 costs $1,010 less than either the Tango Fire 4000 or the Vortex Impact 4000 | ||
The KILO2200 has no environmental sensors. For built-in sensors, choose a Sig KILO3K or higher.
Price Comparison With Environmental Sensors – Tango vs Vortex vs Sightlok
| Part | Tango Fire 4000 | Vortex Impact 4000 | Sig KILO3K + Sightlok RF-1 |
|---|---|---|---|
| Rangefinder | $1,500 for the whole unit, with no environmental sensors | $1,500 for the whole unit, with built-in temperature, pressure and humidity sensors and a digital compass | Sig Sauer KILO3K: $275, with built-in temperature, pressure and humidity sensors |
| Rangefinder mount | Sightlok RF-1: $200 | ||
| Quick-detach kit | Not needed | Not needed | Sightlok QD accessory: $90 |
| Protective cover | Not needed | Not needed | Sightlok polymer protective cover: $70 |
| Total | $1,500 | $1,500 | ✅ $635 |
| Difference | The Sig KILO3K + Sightlok RF-1 costs $865 less than either the Tango Fire 4000 or the Vortex Impact 4000 | ||
If you already own a decent handheld rangefinder, you only buy the Sightlok RF-1, QD accessory and cover, $360 in all, and pay $1,140 less than either the Tango Fire 4000 or the Vortex Impact 4000. The cheaper option is also the better one.
The Verdict
1st Place
A handheld rangefinder in a Sightlok RF-1. The mounted handheld comes out ahead on seven of our eight criteria. The Tango Fire 4000 wins the eighth. See its pros and cons.
2nd Place
Tango Fire 4000. See its pros and cons.
3rd Place
Vortex Impact 4000. See its pros and cons.
Try the Sightlok RF-1 on Your Rifle
With the Sightlok RF-1, you can use the handheld rangefinder you already own.
What is the best WMLRF, or weapon-mounted laser rangefinder?
A quality handheld rangefinder mounted in a Sightlok RF-1. See how the three options ranked.
If I don’t already own a good handheld rangefinder, which one should I use with the Sightlok RF-1?
Pick a rangefinder based on how far you shoot. For ultra-long distances, you may need a Sig KILO8K-ABS or a Sig KILO5K. Most shooters can use almost any decent handheld rangefinder, and the rangefinder doesn’t have to be a Sig. Work out the distances and conditions you shoot in, and buy a rangefinder that handles them.
What warranty do you get on each option?
Handheld rangefinders generally carry strong warranties. Sig Sauer’s Electro-Optics Infinite Guarantee, for instance, is a fully transferable lifetime warranty covering both structural and electronic components. Sightlok backs its own mounts with American support and engineering staff. For the Vortex Impact 4000’s warranty and Tango Innovations’ support record, see the pros and cons of the Vortex Impact 4000 and the Tango Fire 4000.
Who is Sightlok?
Sightlok publishes factual, unbiased reports and reviews on electro-optics gear, especially weapon-mounted laser rangefinders (WMLRF). We are the world’s leading independent expert on WMLRF options. We also design and build the Sightlok RF-1. We help you find gear that fits your needs and avoid gear that doesn’t.
Where does this information come from?
We base these reports on our own field experience with the products, on conversations with our customers, and on posts from respected members of forums like Snipershide, Rokslide and LongRangeHunting.
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Ready to Build a Better WMLRF?
Keep the rangefinder you already own, mount it on your rifle, and co-witness it to your scope.
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Mount your rangefinder to your weapon
The Sightlok RF-1 is a Picatinny / Weaver rail mount that turns the handheld rangefinder you already own into a weapon-mounted laser rangefinder.
