TexasMac wrote: ↑Mon Jan 27, 2020 7:34 pm
Keith,
I can't give you any "come ups" since I have never shot past 500 meters. But will say that's a bunch of powder in a .40 caliber & a flat shooting bullet with only 38 MOA (apparently Brent's math skills leave a little to be desired ). If it's a .40-65 then you're must be using mucho compression? In my Browning .40-65 with 69gr of Swiss 1.5 behind a 402gr "money bullet" the verified velocity is 1330fps. With that load the difference from 200 meter to 500 meters is 49 MOA.
I stand corrected. I grabbed the wrong data for the above comments. Actually the 200 to 500 meter sight difference was 43 MOA with a velocity of 1330fps in the Browning .40-65 with 69gr of Swiss 1.5 behind a 402gr "money bullet".
And FWIW, I just checked recent match data for my Sharps .40-65 with a 414gr "money bullet" ahead of 55gr of Swiss 1.5, resulting in 1225fps. The 200 to 500 meter sight difference was 52 MOA.
Wayne
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book http://www.texas-mac.com
Thanks everyone that replied and for Brents Graph. That all should get me close.
Later when I get organised I will plot a graph as well just to get the curve. I did not think it would be linear but more of a parabola.
I remember reading articles in Gun Digest from back in the 60,s (still Have them) on plotting the mid range trajectory of any cartridge.
Keith, it almost has to be parabolic, but over the range of targets we shoot, it's still pretty darn straight. I'm sure a 2nd order regression would be the best fit.