Truing - Why do calculators just accept one data point?

i_s

Private
Minuteman
Feb 27, 2022
20
8
Colorado
There is something I never understood when it comes to truing ballistic calculators. All of the ones I've tried, like Strelok Pro and Kestrel AB have it so that when you are truing your calculator, you just give it 1 data point at a time. For example, your drop at 1200 yards, then it corrects variables like the muzzle velocity or BC.

Why not allow multiple data points? It seems like you should be able to tell the calculator "here is my drop at 400, 600, 800, 1000", tweak whatever variables you need to get it to match that data exactly for the current environment.

To me this seems like a painfully obvious improvement, even if it would take the calculator more iterations to solve for those variables. In case it isn't clear, the downside of the current approach is that you risk losing data points you know to be correct each time you true one of the variables. Better would be if the calculator would just fill in the things you do not know, not second guess the stuff you already know.

This seems kind of basic, yet I see that it isn't done in any calculator I know of, so I'm guessing something I said above must be wrong. Does anyone know what that is, or why ballistic calculators do it this way?
 
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There is something I never understood when it comes to truing ballistic calculators. All of the ones I've tried, like Strelok Pro and Kestrel AB have it so that when you are truing your calculator, you just give it 1 data point at a time. For example, your drop at 1200 yards, then it corrects variables like the muzzle velocity or BC.

Why not allow multiple data points? It seems like you should be able to tell the calculator "here is my drop at 400, 600, 800, 1000", tweak whatever variables you need to get it to match that data exactly for the current environment.

To me this seems like a painfully obvious improvement, even if it would take the calculator more iterations to solve for those variables. In case it isn't clear, the downside of the current approach is that you risk losing data points you know to be correct each time you true one of the variables. Better would be if the calculator would just fill in the things you do not know, not second guess the stuff you already know.

This seems kind of basic, yet I see that it isn't done in any calculator I know of, so I'm guessing something I said above must be wrong. Does anyone know what that is, or why ballistic calculators do it this way?
Unless you have a very old copy of Strelok Pro it has three distance input if you do a long press on the Trajectory validation button.
The AB mobile app is also 3 distances under Ballistic Calibration.
If you are using a Kestrel Elite "DSF", Drop Scale Factor allows up to 6 distances and can actually "bend" the curve in both directions. I'm not aware of another app that does that.

 
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Unless you have a very old copy of Strelok Pro it has three distance input if you do a long press on the Trajectory validation button.
The AB mobile app is also 3 distances under Ballistic Calibration.
If you are using a Kestrel Elite "DSF", Drop Scale Factor allows up to 6 distances and can actually "bend" the curve in both directions. I'm not aware of another app that does that.

That is awesome RE Strelok Pro. Great info, thanks!

For Kestrel Elite, I knew about that, but it says that is just for "calibrat[ing] the BC of your round beyond the supersonic range of the bullet...". I was looking for something just for the normal supersonic range.
 
That is awesome RE Strelok Pro. Great info, thanks!

For Kestrel Elite, I knew about that, but it says that is just for "calibrat[ing] the BC of your round beyond the supersonic range of the bullet...". I was looking for something just for the normal supersonic range.
It does it both directions, the DSF function is heavily used for rimfire, short of a measured {PDM} it is as good as you can get.
 
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That is awesome RE Strelok Pro. Great info, thanks!

For Kestrel Elite, I knew about that, but it says that is just for "calibrat[ing] the BC of your round beyond the supersonic range of the bullet...". I was looking for something just for the normal supersonic range.
The unspoken problem for most people here is they don't have access to the "transonic distance ranges" where you are supposed to test your BC
 
I've been frustrated with this myself. According to the link to Kestrel's guide " DSF calibration does not impact the supersonic flight path of the bullet." Sometimes it's the midrange numbers that I'd like to correct, but can't seem to make them match the long range without a lot of juggling MV and BC, with a little bore height mixed in for good measure😊
 
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There is something I never understood when it comes to truing ballistic calculators. All of the ones I've tried, like Strelok Pro and Kestrel AB have it so that when you are truing your calculator, you just give it 1 data point at a time. For example, your drop at 1200 yards, then it corrects variables like the muzzle velocity or BC.

Why not allow multiple data points? It seems like you should be able to tell the calculator "here is my drop at 400, 600, 800, 1000", tweak whatever variables you need to get it to match that data exactly for the current environment.

To me this seems like a painfully obvious improvement, even if it would take the calculator more iterations to solve for those variables. In case it isn't clear, the downside of the current approach is that you risk losing data points you know to be correct each time you true one of the variables. Better would be if the calculator would just fill in the things you do not know, not second guess the stuff you already know.

This seems kind of basic, yet I see that it isn't done in any calculator I know of, so I'm guessing something I said above must be wrong. Does anyone know what that is, or why ballistic calculators do it this way?

The AB Mobile update that is soon coming allows up to 7 data points.
 
I've been frustrated with this myself. According to the link to Kestrel's guide " DSF calibration does not impact the supersonic flight path of the bullet." Sometimes it's the midrange numbers that I'd like to correct, but can't seem to make them match the long range without a lot of juggling MV and BC, with a little bore height mixed in for good measure😊

For DSF one input does effect super sonic, but the other 5 will be rejected if they are not subsonic under the current model. We are discussing maybe increasing the number of inputs and changing this though. When you include MV Cal you have 2 Supersonic and 5 Subsonic entries when you combine both of them.
 
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