I've been debating various Sci-Fi vs debates for a while now and I've decided to try and figure out how powerful the C-14 Gauss assault rifle from StarCraft needs to be in order to achieve the following feat: A league is 5.556km, so halfway up a 20 league vortex would be 55.56km from the ground. The standard issue C-14 Gauss rifle fires 8mm DU spikes with a fairly aerodynamic shape (narrow rounded tip and slightly rounded rear) that is either 5cm or 6.4cm long. It is neosteel tipped so I'd assume that's how it avoids getting vaporized by the friction, neosteel being a super hard future alloy. The projectile mass should be somewhere between 43 and 66 grams. Assuming earthlike gravity and atmospheric pressure (it is an inhabited planet), ignoring the winds from the vortex and assuming the Marines were firing at a perfect 90 degrees angle, what would be the minimal muzzle velocity of a C-14 spike to reach 55.56km straight up?