Please Explain Heavy LMG's on Vehicals bullets Dissapear after a certain rang.

What im noticing since months ago when they had the 50cal on the Lav as example. That you could somewhat snipe with heavy guns on vechicals.

Now any thing that has a heavy barrel machine gun wont land past let say 250m.. I can be in any vehicle that shoots and has tracers.The tracers can go well up to 500m+ In a straight line and show a impact where they land.. But the killing bullets never make it there any where close. Im not referring to some embedded bullet spread. Its like the rounds disappear over a certain distance. You can no longer shoot at long distance any more.