Fired from the ISS, and assuming that it's projectile hits nothing - the limits of the universe.
Effective range: between 100 and 400m
Cancer or Scorpio
Scorpio
It would be far, far simpler and quicker to use the calculator on your computer. I could tell you that the answer is 336 but you could not be sure that I had not made a mistake.
Shoot
an m-60 can easily fire 80 rounds in one minute