Please disregard this report and see @Gews much more scientific report here:

https://feedback.bistudio.com/T133383

Thank you

You forgot to account for deceleration of the bullet; something which DayZ simulates. In real life, muzzle velocity of the M4A1 with M855 ammunition is 2900 ft/s (884 m/s), but the bullet at the muzzle experiences a deceleration of 900 m/s², or 92 Gs.

That's a lot. In fact, the bullet will lose ~20%* of its kinetic energy by 100 m. By 500 m, it's lost ~75%*!

The muzzle velocity from the M4A1 might be 2900 ft/s, but the average velocity over 500 m is more like 2000 ft/s. So in real life it would take about 0.8 seconds to reach 500 m.

The SVD starts off somewhat slower, in real life, but the heavier bullet doesn't lose as much speed, and ends up also taking about 0.8 seconds for 500 m.

All that's for real life, and in-game doesn't apply because super wonky new 0.63 ballistic values.

Anyways, I don't trust testing time of flight too much. I tried timing the flight back a while ago and it didn't match my predictions, in that case there seemed to be a small lag between bullet impact time, and the visible splash time on my client. That was a live server. Offline might be better but not sure how accurate, still.

But you're right, ballistics are off (really wildly!!!) and 5.56 should take a bit over half a second at those ranges.