Before you read this.. yes I am aware that NF physics are not RL physics.. but they do follow the general concepts somewhat

In reality.. range of any projectile = (V^2)*cos(2*theta)/g
where
V= muzzle velocity
theta = angle fired at in relation to horizontal
g = acceleration due to gravity

now where shell caliber and weight come in is the muzzle velocity

bigger shell = heavier shell = slower muzzle velocity

this is because of a slower acceleration due to a higher mass

Thus, the reason KM guns have longer range is because they have higher muzzle velocities... as muzzle velocity is the biggest factor in range

/end physics lesson

Now don't flame me about NF=/=RL.. because the dynamics of this game do follow those concepts to a certain degree.... we all know that the physics in this game aren't ideal

Well if you want to talk about real physics-

The range of any projectile is NOT (V^2)*cos(2*theta)/g - that's oversimplifying it.

Range is determined over time by the air drag towards the projectile in motion. This depends on the ballistic coefficient (or coefficient of drag nowadays), the density of the fluid.

It's also depends on the length of the projectile, center of gravity, and the gyroscopic spin on the projectile - which keeps it a relatively stable CD and therefore stable drag throughout.

That's the bigger impacts- the smaller ones include stuff like the Coriolis effect (east-west, west-east distance changes).

So- yes, muzzle velocity is the most important factor (caliber determines muzzle velocity and thus really shouldn't count in NF ranges) but that simple equation you gave is far from the truth of the matter.

Yes, I was extremely oversimplifying it... didn't want to go into a massive physics lesson....... my point was that muzzle velocity SHOULD be the most determining factor in range...

Guys, please stay on topic.
You are talking about NF Physics and this thread has a very specific question that hasn't been answered.