Can Someone Check This Math, Please?

[Wabatuckian]

Hello,

Can someone check this math,please? Before I go plugging it into a spreadsheet? It's a .22LR handload.

Impact  = 0.517490s

Shot start = 0.060320s

T(bullet unadjusted) = 0.45717s

M = 1133fps (75 deg F)

D = 150ft

T(bullet) = T(total) - T(sound)

T(sound) = 150ft/1133s = 0.13239s

T(bullet) = 0.45717s - 0.13239s

T(bullet) = 0.32478s

V(bullet) = d/T(bullet) = 150ft/0.32478s = 461.85fps(avg)

43.5fps avg loss with CCI bullet, avg of muzzle velocity and velocity at 150ft

MV = 505.35fps

My next purchase was going to be a chronograph, then I got laid off thanks to Indiana deciding folks didn't need as much health care as they'd been getting. 'Nuther subject though.

Any help?

Thanks!

Josh

 

[Cain71]

Pie r round,and cornbread is Sq. Thats about all i can due for you.

 

[Regionnus Rattis]

Don't see any math....just a bunch of definitions

 

[Wabatuckian]

V(bullet) = d/T(bullet)

The definitions are all plug'n'chug for that equation.

Thanks,

Josh

 

[Cpt Caveman]

You have fun now!

 

[mhs]

43.5fps avg loss with CCI bullet, avg of muzzle velocity and velocity at 150ft

Where did this come from?

 

[Wabatuckian]

Hello,

Came from the website. Averaged the MV and 50yd velocity, and subtracted that number from the MV.

I think it's sound, but that is one area I'm just not sure about.

Thanks,

Josh

 

[Aszerigan]

Pie r round,and cornbread is Sq. Thats about all i can due for you.

Cornbread squared? You're not using the mix from the box, mister ! Shame on you.

 

[mhs]

Hello,

Came from the website. Averaged the MV and 50yd velocity, and subtracted that number from the MV.

I think it's sound, but that is one area I'm just not sure about.

Thanks,

Josh

I'm pretty sure the loss in velocity isn't linear, so you can't use a simple average. I have no idea how to calculate it correctly, and I also have no idea if the error would amount to anything significant.

Have you tried other distances to see how your calculated mv compares? If you used half the published 50 yard drop with 25 yard times, and got similar calculated mv, that would imply that the error is small.

 

[Wabatuckian]

I'm pretty sure the loss in velocity isn't linear, so you can't use a simple average. I have no idea how to calculate it correctly, and I also have no idea if the error would amount to anything significant.

Have you tried other distances to see how your calculated mv compares? If you used half the published 50 yard drop with 25 yard times, and got similar calculated mv, that would imply that the error is small.

Hello,

I'm going to set up a control at 100yds for this. At 50 yards, a full supersonic round was just too fast for proper analysis.

I'm pretty sure it's not linear too - and the further the range, the more error will be introduced.

I'm sure the true number could be calculated out using ballistic coefficient vs air density, but I have no idea how to do that.

Since the .22LR shows no appreciable drop to 50 yards, but begins to fall off quite a bit thereafter, it would seem the error would be MUCH greater.

We'll see what the 100yd result ends up being.

Thanks!

Josh