- Dec 5, 2001
- Nanty-Glo, Pennsylvania
Is there something missing in our exterior ballistic formula? Example: a 30 caliber 190 gr Sierra MK w/ a BC of .533, w/ a muzzle velocity of 3200 fps has a wind drift of 67.45" in a 10 mph crosswind @ 1000 yds. A 6mm 107 gr Sierra MK w/ approx the same BC .527, w/ the same muzzle velocity and the same remaining velocity, also has the same wind drift @ 1000 yds (68.73") w/ a 10 mph crosswind. It seems that in 6.5mm, 7mm, 30, and 338 this is accurate, but if you were in a shoot-off @ 1000 yd competition and you had your 30 cal (w/ above load) and your 6mm (w/ above load) both rifles being equal in the accuracy department and the wind started to pick up heavy (crosswind) which rifle would you use? Most people I know would use the 30.