TFB Review: BulletSeeker (Speedtracker) Mini Doppler Chronograph

Nicholas C
by Nicholas C

Do you want to get more out of shooting? Have you considered getting a chronograph? Measuring the muzzle velocity of your projectiles is helpful, especially for load development and calculating bullet drop at distance. Well, I bought the Bulletseeker Mach4 chronograph and have been using it this past year so I will share my experience with you.

Chronographs @ TFB:

Bulletseeker Mach4 Doppler Chronograph

I purchased the Bulletseeker last December for two reasons. The first reason is due to my goof in shooting my FX Pocket Chrono with the GR-1 Anvil. 391 grains traveling at almost 300 fps can wreck a chrono if it gets in the way.

The FX chrono costs around $300 so if I was going to replace it I figured I would use that money towards a real chronograph instead. The FX chrono is only good for up to 1200 FPS. While I liked the pocket chrono, I needed to measure muzzle velocity out of my centerfire rifles more than subsonic pistol ammo or rimfire.

I had a Magnetospeed before and so do my friends. However, setting it up and getting the magneto rail/bayonet set up properly is a pain in the rear. I sold it off. Some of my friends have the LabRadar and I was tempted to get one after selling the Magnetospeed but I learned it has its own issues.

So when I shot my pocket chrono, I talked to my friend Kythe and asked him what I should get to replace the FX Pocket chrono. He had just purchased the new mini Doppler chronograph by Longtracker called the Bulletseeker Mach4. Just like my pocket chrono, the Bulletseeker does not have any onboard screens. It uses an app to display the velocities it measures.

The Bulletseeker isn’t cheap. In fact, it costs more than the LabRadar but what makes it potentially better is the fact it constantly emits the radar pulse. LabRadar uses triggers to detect the shot and then emits the radar but sometimes it can cause it to miss a shot if the trigger does not pick up the sound of the shot.

Another issue with the LabRadar is aiming it. I have seen hacks like taping a straw or people 3D printing a Picatinny rail to mount a red dot on it. The Bulletseeker has a Picatinny rail grabber to attach it directly to your firearm. So I ordered one and at the time Longshot Target Cameras was running a sale. It was $100 off for the holidays.

Bulletseeker Picatinny rail grabber

Apparently, the Bulletseeker that Kythe and I got is a newer version. It has a QD lever for the rail grabber. The previous versions used screws and required tools to install and remove it. But as soon as I got my Bulletseeker, I removed the rail grabber to see how it was attached. I had plans to upgrade it with another rail grabber that can mount to ARCA and Picatinny. In the image below, I positioned the Magpul QR Rail Grabber just to see how it would look.

Upgrading the Bulletseeker

I reached out to my friend Eric of Echo Arms and he said he could help make me a 17S adapter for the Bulletseeker. This is what he made. It has two countersunk screw holes to mount the adapter to the chrono and another pair of threaded holes to mount any 17s compatible rail grabber of your choosing.

Originally I had planned to use the Magpul QR Rail Grabber since it was inexpensive and could grab ARCA as well as Picatinny. However, there was an oversight on my part. I did not send the rail grabber to Eric when he designed the adapter for me. The Magpul QR grabber has these protrusions at both ends. They interfere with the adapter for the chrono. So I had to pivot and order an RRS BTC-Pro rail grabber.

Here is the factory mount removed.

My adapter installed on the chrono.

And its final form with the RRS BTC-Pro.

I actually like the RRS more than the Magpul rail grabber. The Magpul designed their grabber so that both angled clamping jaws would grab ARCA or Picatinny. But this requires a lot of movement to go from the narrower Picatinny to ARCA. The RRS has two sets of clamping jaws. The Picatinny one is recessed. So if you want to go from ARCA to Picatinny or vice versa, you do not have to open and close the RRS BTC-Pro that much. It is just faster and easier to use.

Here it is mounted to the ARCA rail on my Desert Tech SRS A1.

Using the Bulletseeker Mach4

When I got the Bulletseeker Mach4 I brought it to the range to chrono my Desert Tech in 6.5 Creedmoor. My friend Kythe was there so we compared our mini Doppler chronographs. Something seemed off with Kythe’s chrono. Using the same gun and same ammo, his Bulletseeker was only giving him double-digit detections.

Screenshot of Kythe's Bulletseeker

You can see the difference between Kythe’s Bulletseeker and mine below.

Screenshot of my Bulletseeker

Kythe reached out to Longshot Target Cameras, whom he bought the chrono from, and told them the discrepancy he was getting compared to mine. They replaced it for him.

While Kythe’s chrono had issues, mine did not seem to have any other than when I tried to measure 5.56 out of my ARs. It would miss shots sometimes. The chrono comes with a parabolic cone that is supposed to help increase detection as well as help minimize false readings from other shooters on the range. Something that can happen with the LabRadar.

Another issue Kythe and I noticed is when we use a suppressor. You need to move the Bulletseeker closer to the muzzle. The manufacturer gives you an adapter that has a single-slot Picatinny rail and V-shaped trough on the other side. So you clamp the chrono to the adapter and use rubber bands to mount it to something cylindrical like a barrel or suppressor. However, since the adapter is polymer, I don’t recommend using it for extended periods, especially on a suppressor.

Kythe ended up mounting his chrono to a Picatinny/ARCA plate and then mounted it to a small table tripod. Now he can position the chrono closer to the muzzle even if he is shooting suppressed.

The downside to doing this is now you have to aim the Bulletseeker to match what you are shooting at.

We did experience another issue when we tried using it with the Noreen ULR Mini .50BMG. We are not sure if the recoil or muzzle blast shockwave damaged it but we only got one speed reading and then it stopped working. The manufacturer of the Bulletseeker does not mention any caliber restrictions. Nor could we find any mention of such information from third-party sources like Longshot Target Camera. So Kythe sent his chrono back in and it got replaced. This time he got the latest iteration called Speedtracker Mach4. You can see the barrel/suppressor mount in the image on the box below.

Longseeker added an LED at the rear of the device. Before it only had an LED at the top of the device where the button was to turn the chrono on and off. As well as enabling Bluetooth connection.

Back in May, my Bulletseeker started to have issues. It no longer measured past 1,000 FPS. Here is a screenshot from when I was trying to measure .308 out of my EBO SAR8 HK91 clone.

I reached out to Longseeker and after sending them data from the App they processed a replacement. I too got the newer Speedtracker Mach4.

Thanks to the help of my friend Thomas, he designed and printed a Picatinny rail that can slide over the Speedtracker body. I will be testing this the next time I hit the range. For now, I mounted it to my gun and did a converging zero with my scope at 100 yards. This way when my friend Kythe or I need to measure the muzzle velocity with a suppressor, it will be much easier aiming the Speedtracker at the same target as the gun when we tripod mount it.

Final Thoughts On The Bulletseeker

My friend Kythe has been using his chrono more frequently than I have and has been tracking various shooters who have been using them. They all seem to have similar issues as we have had regarding the use of suppressors. Kythe and I are a little disappointed in these issues since the device costs $1,000. Right now Longshot Target Camera has them on sale for $850. We still keep using it and so far it keeps working.

There is now a new version called the Speedtracker Mach 4++.

I reached out to Longseeker and they told me this is a new version that will be released next month. It will be showcased at King of The Mile. Here are some highlights they shared with me:

  • Capturing speeds from 213 fps – 4,000 fps (65 m/s – 1200 m/s)
  • Arca Rail Adapter
  • Firmware update
  • App does not change
  • Fully automatic

I am not sure what that last part means but we will learn more when it is released. I hope there is support for early adopters to upgrade theirs to the latest iteration. It feels like we have been beta testers but paid full price. The holiday discount wasn’t much of a discount since they are being sold for less than what we paid.

Nicholas C
Nicholas C

More by Nicholas C

Join the conversation
3 of 5 comments
  • JSATX JSATX on Sep 29, 2023

    I'd like to see you compare this to the new FX True Ballistics chronograph.

    • Nicholas C Nicholas C on Sep 29, 2023

      @JSATX If they want to lend one for a review I’d be down.

  • Jonathan Woods Jonathan Woods on Oct 18, 2023

    I feel like for 850 buck's it should come with several mounting options and you shouldn't have to mod your new toy, not today, not with 3d printers and the availability of doing alot of inhouse R&D. I have an old Caldwell that the display always works, but sometimes the app dosn't pick it up because its a cord and not bluetooth. I had Both magnettospeed's but returned them eventually because they would miss strings. Used a LabRadar and not sold.