Ballistic Coefficients of JSB EXACT 8.44 gr at 400, 500, 600, 700, 800, 900 fps?

[Earl]

What are the Ballistic Coefficients of JSB EXACT 8.44 gr at 400, 500, 600, 700, 800, 900 fps?
I understand the Ballistic Coefficients change at different speeds.
The JSB EXACT 8.44 gr shoots best in several of my guns with different muzzle velocities.
Hard Air Magazine has a Ballistic Coefficient of 0.019 at 940 fps muzzle velocity.

[rsterne]

Come back in 2 years and I hope to have that data for you, once I get my LabRadar….

Bob

[Yogi]

What are the Ballistic Coefficients of JSB EXACT 8.44 gr at 400, 500, 600, 700, 800, 900 fps?
I understand the Ballistic Coefficients change at different speeds.
The JSB EXACT 8.44 gr shoots best in several of my guns with different muzzle velocities.
Hard Air Magazine has a Ballistic Coefficient of 0.019 at 940 fps muzzle velocity.

I thought you were going to tell us.

-Y

[TPL]

Why not to measure by yourself and come back to tell us? You have a chrono? First measure from muzzle 10 shots and calculate average outcome for every speed range. Then put your chrony up to distance you want to know the BC up to and do the same again. Calculate the average. Then use ballistic calculator to define BC and come back with statistics. 

Its not precise like this, I know, but close to it. If you want it to be more precise, shoot 100 pellets...

[Earl]

I think I will keep doing what I have been doing.
I use the BC of 0.019 to calculate the trajectory of the pellets.
I shoot targets at 18, 29 and 49 yards.
Then I adjust the BC and the muzzle velocity in the calculations to match the location of the target groups.

[rsterne]

Conventional wisdom on sample size is 10 per variable.... Since you have two different velocities required (variables) then 20 shots would give you pretty precise averages to use to calculate the BC.... It's actually a bit more complicated than that, the larger the SD of each string, the larger the sample size needed.... but that is the simplified version.... You need to do what you can to keep the ES as low as possible over the 20 shots, of course.... and if you use one chronograph and move it downrange, you want the two strings to duplicate each other as closely as possible.... As with any research or testing, GIGO applies (garbage in, garbage out)….

Bob