It's a problem only with the 7.62mm MXM.

I don't know about feet using setpos(would have to test this) but everything else you listet is in metric measurements, so no inconsistency there. Muzzle velocity is ALWAYS counted in m/s (or ft/s if you're using imperial measurements), that's not an inconsistency. Physics like this are measured in m/s irl, not kph or mph.

The hill to hill distance in the video doesn't look like kilometers. About 400-500m seems correct to me.

This is a problem with dynamic lights. Lightsources like streetlights or the lighthouse loose intensity as soon as the sky starts to light up only a little bit but it's still pitch black outside. It shouldn't be a problem to fix this since headlights of cars aren't affected by this.
Video that shows the problem:
http://www.youtube.com/watch?v=QBSqL0vNz2s

This appears to be a problem before dawn and after sunset. This is on the same date around 2:45AM in the morning:
http://www.youtube.com/watch?v=QBSqL0vNz2s

Don't force aa or af through drivers - schould solve the problem.

I made a quick video of the issue. Note how the lights loose intensity as soon as the sky gets lighter. Dynamic lights should keep their intensity until it's bright enough to see without NVGs.
http://www.youtube.com/watch?v=QBSqL0vNz2s
Video starts at 2:40 in the morning