High drum how do you determine what mph wind your gun is?
Shep
Use a ballistics app, turn off spin drift. Find what wind speed from 9 o'clock causes your bullet to drift 0.6 mil @ 600y(do this my say use a 8mph first time for a 7mag w/ 180berg) once you find the wind speed required for that drift, that's your gun speed.
It should hold true out to 900y for higher bc bullets. So 900y will need 0.9mil adjustment, and say 300y will need 0.3. Once you get to 1000y you'll prob need to add a tenth, so 1.1mil for the 1000y shot.
Temp will have little affect on the formula, but density altitude will make noticeable differences. My rifle that's a 10mph gun at 6000', is an 8 or 9 at 2000'. It's a very handy formula.
Here's a ballistics chart of my norma imp w/245 Bergers at 2950fps. 10mph wind, see how the mil hold in tenths equals the 1st digit of yardage.
If I'm shooting in a 15mph wind, at 750y, I take my know constant of 0.7mil for 700y and take it x1.5, wind hold is now 1.1 mil. In a 4mph wind @ 750y, 0.7x 0.4 hold is now 0.3 mils.
This was my eye opening moment when I realized mils is truly more useful. It's not better per se, but more applicable when holding wind, and making easier hands on dope in the field. It's cost me a fair bit of money to swap all my scopes out, but if it makes me a more efficient rifleman, I'm all about it.