Back in World War Two, the Russians developed an experimental weapon called so eloquently "Fire Hedgehog" that fired 88 ppsh submachine guns straight down as a volume strafing device. Knowing quite a bit about straight line ballistics, i was curious to know more about the effectiveness of this device. So here is the question that I could not figure out. Question: At what height would would the aircraft have to obtain for this device to be effective, and subsequently at what height would this weapon pose no threat? At some point the initial velocity of the bullet being fired will be lost due to wind resistance which is more of a fluid dynamics question and will need to be figured out in order to get this to work correctly. Below I will set up the experiment with as many variables as I can think of: Experiment: Aircraft: Russian Tu2 Traveling at 379mph or 555fps. Weapon: Russian PPSH Submachine gun statistics: Muzzle Velocity 488 m/s (1,600.6 ft/s) Fires the 7.62x25 Tokarev Bullet Statistics: Bullet Diameter .310in Bullet Weight 5.5g Velocity 525 m/s (1,720 ft/s) Energy: 760 J (560 ft·lbf) Atmospheric Conditions: Altitude: 0 MCL Lateral Wind: 0 Temperature at 0 MCL: 32F (0c) If more variables are needed let me know and i will attempt to supply the rest.