I wouldn’t say just hitting an target as large as an military helicopter isn’t hard. I’m a an old farm boy who hunts occasional(more occasionally as I age)(Deer, quail, dove, groundhog and occasional nuisance dog, coyote etc.)that lives near Fort Campbell and we see them flying every day. A thousand feet is very doable.
Now, that’s just hitting it.
Hitting it with the idea to bring it down is another subject and even my basic skill (as a civilian) shooter wouldn’t dare to offer advice on how to bring one of these ‘birds’ down.
These pilots fly pretty low so you can see their faces and they can see yours so you keep you weapon at a respectful position when you hear them approach.
Nowadays with their optics i daresay they can see you at a far distance and in all conditions so getting a wild hair up your a$$ and try shooting at one of these aircraft ain’t the smartest idea one can come up with.
Unlike boys throwing rocks at a passing train that can't stop, aircraft can circle and return fire.
There's a dangerous time in every boy's development when he tests what he can do to the world, not sure yet if he has any effect, sometimes shooting things, playing with explosives, vandalizing. Hopefully he makes it through the eventual "oh shit" moment without hurting himself or others, but sometimes not.