Like when people fire their guns into the air, what happens to them? Do they go up into low orbit, do they burn up, do they land somewhere else?
They hit the ground somewhere traveling at 300 ft per second(approximate terminal velocity of a 30 caliber bullet)
They are not fired with nearly enough speed to leave the atmosphere, nor to burn up due to friction with the air.
What goes up, must come down.
If you are in the country, odds of shooting a person are pretty small, but obviously that increases with increasing population density and shouldn’t be done anywhere.
They come down nearby – they’re nowhere near fast enough to make it to orbital heights.
If they’re shot mostly upwards they tumble and fall much slower than muzzle velocity.
If they’re shot more horizontally they can continue traveling at lethal speed and kill someone a half mile away.
If they are shot straight up they will end up losing all speed and on the way down they do not pick up as much speed due to the air resistance. So the bullets do not land with the same energy as they are shot out of the gun with. It is hard to say it could not be dangerous or even lethal but it is more similar to the dangers of ricochets then actually getting shot directly.
However there is a much higher danger with bullets that is shot upwards at an angle. Say the shooter holds the gun at a 45 degree angle instead of a 90 degree angle. In that case the bullet does not lose all its speed as it goes up but will instead go in an arch. It will still lose a lot of energy but a lot less then when shoting straight up. And although the bullet will probably hit well outside of the effective range even ineffective fire can be lethal. And people have been killed at celebrations due to gunfire into the air. And this is why when you train on shooting you are always instructed to discharge the gun towards the ground in a safe direction, preferably into a pile of sand.
The MythBusters actually covered this one! It mostly depends on the angle you fire it at, but all of them definitely come back down. https://mythresults.com/episode50
Eventually they lose their velocity and start falling down at terminal velocity, which is much lower than the speed at which they fly out of the barrel.