FX True Ballistic Chronograph - Testing & Results

Jump to latest Follow Reply
I might be misunderstanding what it's doing, but it sounds like you're getting an "effective BC" given your current conditions.

That would be great for that days shooting, in that location, but it seems like you'd want the "real" BC - that is, a BC that's been normalized to "standard atmosphere" - which should very closely match the "book" value (if there is one). With the "real" BC you can adjust according to conditions where you are at some other place and time. With an "effective BC" you'd have to back-calculate to a "real" BC then calculate a new "effective" BC. This would be a fairly manual process in any of the ballistics software that I've used.

I've never heard anyone use the term "effective BC" before - that's just what I'm calling it. But a BC that takes into account specific atmospheric conditions (other than the "standard atmosphere") should at least be called something different as it wouldn't be directly comparable to the numbers presented by any ballistician.

GsT
 
  • Like
Reactions: drsquall and Macros
Upvote 0
GeneT said:
I might be misunderstanding what it's doing, but it sounds like you're getting an "effective BC" given your current conditions.

That would be great for that days shooting, in that location, but it seems like you'd want the "real" BC - that is, a BC that's been normalized to "standard atmosphere" - which should very closely match the "book" value (if there is one). With the "real" BC you can adjust according to conditions where you are at some other place and time. With an "effective BC" you'd have to back-calculate to a "real" BC then calculate a new "effective" BC. This would be a fairly manual process in any of the ballistics software that I've used.

I've never heard anyone use the term "effective BC" before - that's just what I'm calling it. But a BC that takes into account specific atmospheric conditions (other than the "standard atmosphere") should at least be called something different as it wouldn't be directly comparable to the numbers presented by any ballistician.

GsT
Click to expand...
Hi Gene,

Ballistician sounds good when I say it, but I have so much trouble spelling it!

I haven’t “proven out” any of the results, but my experience tell me that an “average” BC is not as precise as multi-bc’s.

I got the results during specific atmospheric conditions (shown as Weather when zeroing) and next time I shoot I’ll be sure to update the ballistic app with the Current Weather. Which during hypothetical testing has yielded different results than that of the zeroing results.

IMG_3237.jpeg
 
  • Like
Reactions: FX Airguns, Centercut, Str8tshooter and 1 other person
Upvote 0
Its finally beautiful outside here, and I should be outside shooting, changing oil, and doing yard work......but nope.
The subliminal message at 1:25 has caused me great mental injury!
I now find myself wasting valuable time, sitting here catching up on airgun related information at AGN.com !
Be prepared to hear from my attorneys, first thing Monday morning!
LOL!
 
  • Like
Reactions: GeneT
Upvote 0
I did some 100y testing at the Misenheimer Ranch. Figured I’d pass along my findings.

1. The True Ballistic Chronograph is super easy to setup & use. I lined it up directly beneath the muzzle and it didn’t miss a single shot.
2. Atmospheric conditions affect the BC! Use the FX Radar app and select the option “send local weather to device”.
3. If possible record data out to 100y+. The BC most definitely changes as the velocity decreases.
4. While an average BC can be useful, multiple BC points are even better.


IMG_3300.jpeg

IMG_3304.jpeg

IMG_3301.jpeg

IMG_3299.jpeg


IMG_3297.jpeg
 
  • Like
Reactions: Centercut
Upvote 0
I've been using one of these for comparing different slugs BC and velocity consistency.
Great little unit. Very happy with it. Reads every shot even in the dark.
Don't assume that it reads at multiple yardages though.
It takes two readings, near the muzzle and somewhere inside of 33 yards and fills the rest in with a ballistic calculator.

FX_Chrony.jpg


FX_Chrony2.jpg


FX_Chrony3.jpg

The unit doesn't read at all those yardages
That being said, I still think this is a very handy chronograph.
 
Upvote 0
Long_Shot said:
I've been using one of these for comparing different slugs BC and velocity consistency.
Great little unit. Very happy with it. Reads every shot even in the dark.
Don't assume that it reads at multiple yardages though.
It takes two readings, near the muzzle and somewhere inside of 33 yards and fills the rest in with a ballistic calculator.

View attachment 450213

View attachment 450214

View attachment 450215
The unit doesn't read at all those yardages
That being said, I still think this is a very handy chronograph.
Click to expand...
Is there a good reason to get this instead of a Labradar that reads real velocities ?
 
Upvote 0
Long_Shot said:
I've been using one of these for comparing different slugs BC and velocity consistency.
Great little unit. Very happy with it. Reads every shot even in the dark.
Don't assume that it reads at multiple yardages though.
It takes two readings, near the muzzle and somewhere inside of 33 yards and fills the rest in with a ballistic calculator.

View attachment 450213

View attachment 450214

View attachment 450215
The unit doesn't read at all those yardages
That being said, I still think this is a very handy chronograph.
Click to expand...
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
 
  • Like
Reactions: Centercut, Hajimoto and DesertSilver
Upvote 0
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 www.airgunnation.com
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu