Click the link and enable the Excel advanced option: formulas - iterative calculation.
Forgot to mention: If you don't have (and don't care to pay for!) Excel, PaperChrony also opens and works with the absolutely free Open Office Calc
Download here: https://www.openoffice.org/ and LibreOffice https://www.libreoffice.org/discover/libreoffice/
Original post from the Yellow archives -- 2017: https://www.tapatalk.com/groups/yellow/working-math-for-a-paper-chrony-that-measures-both-t237889.html#p2697953
Nice resource, but I find that the output is extremely sensitive to input parameters.
For example, if I use real world data from Chairgun I get the same BC and velocity as chairgun. However, even a small change ot .01" to scope height changes velocity output by 6 fps. Changes to drop inputs are even more sensitive.
Drop data can be calculated solely on the basis of curve fitting in excel ( using a 3rd order polynomial), but it's helpful to have 4-5 data points.
No scope height, bc, or MV are needed.
K
Nice resource, but I find that the output is extremely sensitive to input parameters.
For example, if I use real world data from Chairgun I get the same BC and velocity as chairgun. However, even a small change ot .01" to scope height changes velocity output by 6 fps. Changes to drop inputs are even more sensitive.
Drop data can be calculated solely on the basis of curve fitting in excel ( using a 3rd order polynomial), but it's helpful to have 4-5 data points.
No scope height, bc, or MV are needed.
K
Thanks. Meanwhile...
Curve fitting is certainly useful for interpolating empirical drop data with a given setup, but it won't help you much in, for example, predicting how trajectory will change if you change pellet, tune, or scope height without having to start over from scratch at the range.
For that you need MV and BC.
And some physics.
For the benefit of anyone new to FT I'm adding the following comments.
As an FT shooter, if I change anything I'm re-shooting dope. The only thing I trust is what I see under real conditions. Even Chairgun can offer viable drop solutions where wind drift is off. It takes time to get it all right.
Curve fitting is possible and is quite accurate especially if you go to an absurd length, such as 6th order polynomial fitting, but I don't know of anyone using it in FT.
For the benefit of anyone new to FT I'm adding the following comments.
As an FT shooter, if I change anything I'm re-shooting dope. The only thing I trust is what I see under real conditions.
Understood.
In which case I'll just say I hope PC provided a minute or two of pleasant diversion, which was its main purpose in the first place as an answer to the eternal (occasional) question: How to measure MV without a chronograph?
