A case from just last night, apparently: http://www.cnn.com/2012/01/01/us/florida-celebratory-gunfire/index.html
According to Terminal velocity - Wikipedia
USMC has found that a 30-06 bullet has terminal velocity of around 200 MpH (about double what the mythbusters calculated). I THINK this is due to their assertion that a bullet straight up would not spin (spin would lower its wind resistance, raising its TermV.)
Even if the spin stopped as in a “straight up” case, wouldn’t the fired bullet spin on the way down due to irregularity of the surface?
Also, how do you define straight up? Wouldn’t the bullets position RELATIVE to the movement of the air be important?
No, what is important is the bullet’s position relative to the gravity field. “Straight up” is opposite the pull of gravity. Because that gravity field is what is providing the energy to slow the bullet down to zero and reverse it’s fall. If the bullet is shot straight up, then gravity removes all the initial velocity, and the imparts a downward velocity that is limited by drag. Thus terminal velocity comes into play.
If the bullet is not fired straight up, then some of the initial sideways velocity can continue with the bullet as gravity curves the trajectory. Thus the drag never slows the bullet down to the “safe” speed. Ergo, bullet impacts with a much higher energy and can kill. Even if traveling downward at the time.
Wind in the vicinity only affects where the bullet comes down, it does not affect whether the bullet lost all initial velocity in the climb.
Look, for the specific question of the ideal case, a bullet fired straight up will not have enough energy to kill most people.
The real world is almost never the ideal case. It is ridiculous and irresponsible to fire guns into the air as a means of celebration. Anyone who does so is forcing everyone in the area into a game of Russian roulette - perhaps one with a low payout rate, but still.
I think it should be fitting punishment to force them into a personal game of Russian roulette with a higher payout rate - say six bullets. (Or a semi-auto.) YMMV.