Today, I finally got tired of waiting for the wind to stop blowing and shot in the wind. I didn't crono today, the wind would have blown the crono over.
Conditions were 65 deg, wind quartering away from left to right 15-36 mph. Humidity 17%, Barometric pressure 29.84.
There is an airport near the range so I got wind readings from their web site.
Loads were: Barnes 160gr TTSX, .400 BC, SD .219, Cartridge OAL 2.85", .050 off lands, Fed 215 Primers, RL17 powder.
The 2 targets on the left had 68.3 charge. 0.002" and 0.000" headspace.
The 2 targets on the right were 68.7 grains 0.002 headspace and 0.000 headspace.
Two things I take away from this is; headspace doesn't make much difference and this bullet is pretty stable in windy conditions.
Quick load estimated velocity: 3258 fps.