Wind value
- Thread starter XLR8
- Start date
- Location
- Somewhere on the Hudson Bay Coast
You can plug your ballistic data into a ballistic program using a 10 mph full value wind, then half it for a light wind or double or triple it for a strong wind. The same for shooting in a half ar quarter value wind. Fortunately, wind calculations don't need to be dead on, and good shooting can be accomplished as long as your WAG is within 5 mph.
I actually like a formula I found in "The Ultimate Sniper" some years ago. Multiply the wind speed by the range divided by 100, so 500 yards in a 5 mph wind would be 5X5=25. This amount is then divided by a range critcal mathematical constant which up to 500 yards is 15, 600 is 14, 700 13, 800 is 13, 900 is 12 and 1000 is 11. At 500 yards we would divide by 15 so we get 1.66 MOA, so would adjust 1.75. The constant must be tweaked for your particular bullet and velocity, but this can be easily done from the ballistic program, or from your observations when shooting.
Does it work? Shortly after I discovered this marvel, I was out shooting on a particularly unpleasant winter day on the Churchill River with a pal who is a wonderful long range shot. The constant, full value wind speed, was 60 clicks with gusts to 70. He challenged me to work out a solution to put him on paper at 600 yards. Using the basic formula he shot a 4" group a half minute off center with with his .25/06 Sendero from prone. Since then I've liked that formula, and I have worked out the constants for all my long range loads.
I actually like a formula I found in "The Ultimate Sniper" some years ago. Multiply the wind speed by the range divided by 100, so 500 yards in a 5 mph wind would be 5X5=25. This amount is then divided by a range critcal mathematical constant which up to 500 yards is 15, 600 is 14, 700 13, 800 is 13, 900 is 12 and 1000 is 11. At 500 yards we would divide by 15 so we get 1.66 MOA, so would adjust 1.75. The constant must be tweaked for your particular bullet and velocity, but this can be easily done from the ballistic program, or from your observations when shooting.
Does it work? Shortly after I discovered this marvel, I was out shooting on a particularly unpleasant winter day on the Churchill River with a pal who is a wonderful long range shot. The constant, full value wind speed, was 60 clicks with gusts to 70. He challenged me to work out a solution to put him on paper at 600 yards. Using the basic formula he shot a 4" group a half minute off center with with his .25/06 Sendero from prone. Since then I've liked that formula, and I have worked out the constants for all my long range loads.
was thinking the same thing
"...figure out the wind correction value?..." You can't. The wind is never a constant. You have to learn to read the wind and mirage.
Which 4895 powder? IMR4895 isn't a .300
Try some 190 grain Matchking bullets with IMR4350 or IMR4831. Good ammo needs to be meticulously loaded too. Starting with having the brass all the same length and weighing each powder charge.
Which 4895 powder? IMR4895 isn't a .300
Try some 190 grain Matchking bullets with IMR4350 or IMR4831. Good ammo needs to be meticulously loaded too. Starting with having the brass all the same length and weighing each powder charge.
