I don't have an Uzi, myself, nor have I ever held one in my hands. But in my novel, Unholy Quest, an Uzi pops up in the story, and goes pop pop pop.
Now, as it happens, guns vary quite a bit. Yeah, they all have gunpowder behind a projectile, and a trigger to set off the gunpowder, but there is a lot of variation in how they work. So it is dangerous to just assume, when writing a story, that you know how a certain kind of gun works in any detail at all.
Some years a go I read a story by a quite successful author, in which the hero was holding a revolver and flipped the safety off.
Well, there may be some exceptions, but as of that time, revolvers did not have safeties to flip. That's one thing I do know.
Gun loving readers get particularly upset when you get firearms details wrong. Perhaps it is because gun lovers are the targets of so much abuse. These guys actually know a great deal, and practice very safe gunhandling, but the press treats them as a bunch of ignoramuses. Well, they aren't. And among themselves they are amused and outraged at the misconceptions that regularly appear in the press.
Here's a nice little article for writers about firearm basics:
Rhyme of the day:
If you want to know about guns,
Distrust the media.
Better to get your hands on
A gun encyclopedia.