Ah, didn’t realize that’s what they did. I thought they just fired fake guns (eg something like an airsoft gun with gas blowback or something fancy )and edited the sounds in later.
From what understand, guns are silly loud. Much louder than they sound in movies.
But I’ve never fired or even held one, so what do I know :)
The hot and cold water thing is not common at all. A few sushi places and bars have it. But it’s quite rare tbh.