Bullet Range/Distance calculator?

[Time for Change]

May I request information from our shooting gurus regarding calculators (programs) that will assist with determining the distance a bullet will travel before gravity takes it to the ground?

For instance:
One is firing a 7.62x39 124 grain FMJ projectile from a standing position from an SKS
the gun height is +/- 5'-6" and the scope is +/- 1.5" above the barrel
the advertised muzzle velocity is +/- 2396 f/s (per manufacturer)
the terrain is relatively flat, with vairance no more than 24"
the range is estimated +/- 100 yards but may be increased to 200 yards after zeroing at 100 (just for kicks)

Simplified estimation indicates that a projectile dropped from this height by hand will reach the ground in +/- 1 second.
so, if gravity will ground it in one second (gravity being a constant regardless of the horizontal velocity), is seems that the round will travel only +/-2400' before gravity sinks it in the dirt.
Is that correct?
That is reasonable I suppose, but I'd prefer an accurate program to "chart" the potential distance if in any way possible.

It seems that a program, in theory, would allow me to estimate the distance a round would travel if gravity was completely removed from the equation too?
How far can it potentially travel before it's energy is completely dissipated by wind friction?

I know this request seems odd, but it is relatively flat around here, and one must consider the possibility of a round hitting a rock as it intersects the ground and ends up being projected further down range by it's own remaining energy / momentum.

Does that make sense?