[Spaceships] Conventional and EM Gun ranges in atmosphere?

[Anthony]

Originally Posted by vicky_molokh

I have trouble parsing that - my math is very rusty (the equation-related parts, anyway). Sorry.
What is 'k'?

What I was trying to say was that more powerful throws do result in greater range, so if range is proportional to calibre only, something seems missing.

k is an unspecified constant. Half damage range is strictly a function of projectile sectional density and drag coefficient. Actual maximum range is a rather complex function, because it involves both atmospheric drag and gravity, but is pretty heavily dominated by drag unless dealing with projectiles that are quite large or quite slow (at least, by bullet terms. A thrown rock is both large and very slow by those terms).