> In the case of a bullet fired at sufficiently close to a vertical angle to result in a nonballistic trajectory, the bullet would tumble, lose its spin, and fall at a much slower speed due to terminal velocity, so is rendered less than lethal on impact (the Busted rating). However, if a bullet is fired at a lower angle allowing for a ballistic trajectory (a far more likely case), it will maintain its spin and will retain enough energy to be lethal on impact (the Plausible rating). Because of this potentiality, firing a gun into the air is illegal in most U.S. states, and even in the states where it is legal, it is not recommended by the police. Also, the MythBusters were able to identify two people who had been injured by falling bullets (fired from about 1 mi (1.6 km) away, hence at a lower angle), one of them fatally (the Confirmed rating). This is the only myth to receive all three ratings at the same time.
[1] https://en.wikipedia.org/wiki/MythBusters_(2006_season)#Epis...
There is a huge difference in difficulty between 30 degrees, which is easy enough to eyeball, and 3 degrees which requires careful aiming with a specialized tool.
It will be much less than that on the way down due to air resistance throughout the flight, and negligible compared to terminal velocity (around 200 fps).
The reason perfectly vertical bullets are less dangerous is that they tumble and this tumbling reduces the terminal velocity below dangerous levels. Presumably tumbling could also happen at lower angles due to wind or other factors, it just is less likely.
Goes to show people believe the thing that's most convenient for them to believe.
Related, this Forbes articles explains the matter and links to a few documented cases:
https://www.forbes.com/sites/startswithabang/2020/07/02/the-...
The non-lethal was only if the bullet was fired perfectly straight up using precision alignment. It seems to be a common disinformation tactic to take this section out of context and claim that Mythbusters said shooting up was fine.