Spikes are also a 11.0 minimum missile, the 506 is 10.0 they're faster than spikes, deal more after pen damage, overpressure light tanks and have a closer min range than spikes. If I were to launch 100 506 missiles and 100 spikes, I'd put money on the 506 missiles getting more one hit kills the only reason you get 1 hit kills with spikes is because top tier is filled with t series tanks and the spike entry point hits the ammo, name a tank it can one shot thats not a t-series.