FX True Ballistic Chronograph - Testing & Results

[Centercut]

I spoke with Johan about this. It is true that in your scenario much of the results you are seeing are calculated. Here's some more information to help everyone understand this:

• When setup properly the doppler radar will take hundreds of readings throughout the flight of the projectile (the 1st reading is taken after 10-15 yards).
• Currently the most accurate readings are at 150y or less.
• If you notice at the top of the display you see 1/5, 2/5, 3/5. This refers to how well of a reading was taken. 1/5 and 2/5 are really bad and chances are you're getting more calculations than raw data. 3/5 is better, but obviously 4/5 and 5/5 would be best. The raw doppler data can be improved by minimizing interference and properly placing the chronograph in line with the path of the projectile.
• A new feature is in beta testing that will allow the end user to decipher between the actual doppler data and the calculated data. This will become available as a free firmware download in the near future.

Cheers
-Michael

Thanks Michael, good data. I've been using mine for quite a while now, and always set it up when I'm shooting bench. I've found a few items from testing.

1. When shooting at "just" 50 yards, the BC will be different than when shooting at 100 yards. It is USUALLY higher when it gets to measure additional data points.
2. I set my distances to 20, 45, 70, and 95 yards. This way at 100 yards, I get the muzzle velocity plus 4 data points. Even when shooting 50 yards, the machine uses 2 data points plus muzzle. If its set like some of the above at 100, 150, 200, and 300, you're not getting the benefit of using multiple data points and only getting muzzle and maybe 100 yards. It's pointless to set it up at farther than 100 yards.
3. MOST of the standard slugs will benefit from using the RA4 profile vice the G1. For boat tails, using the G7 profile will get your most accurate data. Don't let your ego affect your choice, since G1 will give you a higher number!

I appreciate the information of x/5 at the top, I always wondered what that was for...

 

[Ballisticboy]

Michael,
I believe there needs to be some clarification on how the TB Chronograph takes readings and displays the results. I had a conversation on AGN with one of the developers of the TB App about this very topic. The conversation started because I used the TB when I was shooting some of the AGN 30yd Challenge cards and I had it set up to give speeds at 10, 20, 30 and 40 yds. I shot the target and got velocities at all four ranges - only the pellet stopped at the wood backing of my target at 30 yds. So I figured that the velocities provided were CALCULATE and not MEASURED.

Below is a link to a conversation I had with AGN member "fiske" who stated that he is one of the developers of the software and app for the TB Chrono. He states that because they are sampling at about 1mHz they are doing the DSP in real time and do not store the raw data. So any data that they can output will have significant processing on it (a good thing actually). What I also got from this conversation was that the return signal from the pellet gets worse with range (see the spectrum he provided) and there is definitely a range limit on the radar (appears to be something like 100msec - so at our velocities something like 30-40 yds). So I expect the data it is providing at 100 yds is an extrapolation based on the ballistics calculation. The typical ballistics calculations done on a smart phone are estimates and only deal with drag in terms of known ballistics profiles, not computational fluid dynamics.

What I am trying to say is that while your BC calculation efforts are well intentioned and a good idea, I don't believe you will be able to do what you want with the TB Chrony. I would be happy for fiske or Johann to explain why I am incorrect in my reasoning.

Cheers,
Greg

Whats the actual benefit of the "FX true ballistics chronograph?"

I already have an FX pocket chrono, and a ProChrony. They work fine to tell me my muzzle velocity. The value they provide -> velocity & reg tuning. Power verificaiton for FT and EFT. Benefit of the FX True Ballistics chrony: 1) Provides actual average BC based on my equipment, pellet...

www.airgunnation.com

After working analysing the data from Doppler muzzle velocity radars for over 20 years, If that is what they are doing, it seems a shocking waste of the radars capabilities. Our experience was that the radar developers are not the best people to analyse the data, that needs to be the ballistic users who know what they are looking for and what the best solution is. The curve fitting for the data is a vital component which can easily give large errors if not done properly. The data does not have to be the exact raw data, the files would be too massive, but it should be available over suitable minute time steps with minimal processing. The true processing can only be done when there is a complete track available, trying to do it in real time will be subject to errors which would be seen when the full track is available.

The radar cannot be used to produce purpose drag laws if that is how they are producing the data, so you are stuck with their choice of reference drag law and their interpretation of how it best fits, or doesn't fit. The Labradar seems to be far superior in its possible uses.

 

[Scotchmo]

Ballisticboy,
Right on. It’s overkill if I just want a convenient way to get muzzle velocity, but I like my Labradar a lot. At the range, it gives multiple distance velocity readings, which is nice, but most of the work happens later. At home, I transfer the Labradar SD card to my computer and bring up the data spreadsheets for entire shooting sessions. Analyzing the data, I can spot data points that are “bad” and ignore them. It is somewhat laborious, but.using a ballistics app, it’s possible to see which drag model (G1, G7, RA4, SLG0, etc.) best matches the spreadsheet data for a particular projectile and velocity range. With enough data, it’s possible to see subtle trends. After three years of using my Labradar, I wouldn’t settle for any other radar that did not give easy access to all of the raw data.

 

[Altaros]

Ballisticboy and Scotchmo​

I fully agree with you, the inability to easily process data (in Excel) is one of the worst features of modern chronometers.
I have pretty much all the important chronometers these days LabRadar, Garmin and the aforementioned FX chrono.

I choose LabRadar for BC measurements, but I mostly use Garmin for regular MV measurements, as it is perfectly transportable and ready very quickly.
paradoxically the name: FX True Ballistic Chronograph has the fake word True already in the name. For me the worst chronograph I have, because for example the BC measurement of our BT slugs ATP measures absolutely tragically and it doesn't matter whether it is .22 40gr or 6mm 100gr or .25 caliber.
I'm not saying it's a bad chrono for centerfire shooters, for example, where it measured well in the test, but they can't advertise correctly measuring BC at a distance of hundreds of yards, when in reality everything is measured up to 80-90 yards and as I already mentioned, BT slugs can't measure well even at 30-40 yards.The inability to analyze like LabRadar is just another minus this chrono has.

If they could make a proper measurement BC that would differ from shot to shot really minimally, for example when setting the measurement to only 20-30 yards, then I would say, yes, a good product, but when BC measurements differ from shot to shot by 30% at our slugs, then these are just bullpoop results.
Here are the results that the chrono regularly gave me and where you can clearly see the brutal % difference in measurements:

 

[Altaros]

as you can see, the real measurement is only the last photo from .308 centerfire, the other BC results jump by tens of %, while the reality is that the given BC slugs do not differ by even 1%.

Moreover, giving measurements at a greater distance of hundreds of yards is complete nonsense.
Example of measurements of the European LabRadar and one of our slugs, this is a graph of SNR from data for one shot, where it is clearly see how at 30-40m (the graph has flight time on the lower axis) the speed starts to change significantly in each sample and it is therefore see that the signal quality starts to decrease significantly and therefore this speed data is no longer valid.

Let no one tell me that the FX chronograph has this level many times better, when even the same slugs cannot measure correctly at 30-40m.
if they make a functional fix for FX so that their chrono measures real BC data for echt shots, I'll feel free to write " ok, it's working properly now and is good chornograph" and I'll start using it for quick BC measurements when developing new CNC slugs, but until then it's just a "fake" chronograph for me.
This is a user's statement, not a slander of a competing company

 

[bchannell]

Im far from a ballistics expert, bout as far as you can get, really, but i have a couple questions.
1) Are ANY of the radar chronos capable of "seeing“ a [for instance] 177 pellet past, oh say, 30, 4 , or, 50 yards?
I've seen some review of these units, and i have a Garmin, and i wish someone would test these chronos in "worst case conditions“ with 177 pellets. If it works, at distance, for them, then it can measure anything.
Can the LR see a pellet past 40 or so yards?

2) The bc thing is sort of academic for the vast majority of shooters, won't we always need to shoot and verify, and adjust? Which is a good thing.

 

[Smok3y]

Im far from a ballistics expert, bout as far as you can get, really, but i have a couple questions.
1) Are ANY of the radar chronos capable of "seeing“ a [for instance] 177 pellet past, oh say, 30, 4 , or, 50 yards?
I've seen some review of these units, and i have a Garmin, and i wish someone would test these chronos in "worst case conditions“ with 177 pellets. If it works, at distance, for them, then it can measure anything.
Can the LR see a pellet past 40 or so yards?

2) The bc thing is sort of academic for the vast majority of shooters, won't we always need to shoot and verify, and adjust? Which is a good thing.

Haven’t used one but the new Caldwell Velociradar gets data at 10 points down range. I don’t know of another doing that.

 

[bchannell]

I emailed Caldwell and they did not give encouraging info on the use of the VR with pellets. The wording wasn't “heck, yeah, it'll work“, more like.... "it might, but can be problematic“.
And, again, i'm guessing the VR is calculating velocity at some of those distances.

 

[Ballisticboy]

Haven’t used one but the new Caldwell Velociradar gets data at 10 points down range. I don’t know of another doing that.

If the Velociradar only gets data at 10 points down range, that would make it the worst Doppler radar ever. Doppler radars do not work like that, they continually measure velocity as a function of time, with some measuring distances as well, until the signal is lost. The data gathered is then used to calculate velocities at fixed distances, which are what is presented on the screen. The problem with that is that we do not know how the data was used in the calculations, and what is the quality of the data used. That is why it is necessary to use the raw data, or as near to it as we can get, to be able to assess the quality and usability of the measured data.

 

[Smok3y]

If the Velociradar only gets data at 10 points down range, that would make it the worst Doppler radar ever. Doppler radars do not work like that, they continually measure velocity as a function of time, with some measuring distances as well, until the signal is lost. The data gathered is then used to calculate velocities at fixed distances, which are what is presented on the screen. The problem with that is that we do not know how the data was used in the calculations, and what is the quality of the data used. That is why it is necessary to use the raw data, or as near to it as we can get, to be able to assess the quality and usability of the measured data.

Interesting. I don’t know the first thing about the details on Doppler vs Radar. This does bring a question to mind then, wouldn’t those 10 data points still be better than a radar unit that only measures 1 point or 4 points??
I like my radar unit with what I think is 1 point of measurement, but this does make me curious as the sales data on that Caldwell make it seem superior.

 

[bchannell]

My guess is, no radar only uses one point for data. It likely uses many to increase it's accuracy.

 

[beerthief]

This is a Hobby , you can do what ever tickles you . Whatever makes you happy . Their is no price tag on happiness.
Stan in KY.

 

[JungleShooter]

Well, it has been a futile battle over the past few years — I tried to resist, with a rather limited success — but I admit I often could not resist the urge my finger presented me to clicking the rectangle "Start Conversation" when someone offered a used Caldwell or FX (model 1) chronie.

So, now I have two Caldwells, and a couple of Gen.1 FX's (those break somewhat unexpectedly).
And I will go the old school route...:

➊ Shoot through all the chronies at the same time — and measure their divergence (to take into acocunt when measuring real shots).

➋ Adjust the scope on the gun for a 100 yard shot.

➌ Point the gun on bipod and bags at the target 100y away.
While the reticle is on the bull's use a laser mounted to the gun and adjust it to point also to the bulls.

➍ Place an FX (Gen. 1) at the muzzzle.
➎ Place a Caldwell at 50y.
➏ Place another Caldwell at 100y.
Use the laser from point ➌ to set up the chronies.

➐ Start shooting, recording the velocities at the different ranges by hand, using the scope (at high magnification) to read the numbers on the 50y and 100y chronies.

➑ Use the GPS Ballistics calculator to calculate the BC of each shot.
Come up with a reasonable average, discarding outliers.



➧ I HATED physics and math in school.
➧ I LOVE this!!

Matthias

 

[.20calguy]

Utah $899???? NOT 229?

$229 is probably one like mine. The FX pocket chrony.