Okay, fine then. What happens is that you pull the trigger and the bullet flies through a hidden invisible tube that leads out near the back of your head where a camouflaged pouch of fake blood is hidden. Then it punctures the blood pouch making it look like you killed yourself. (The barrel of the gun also squirts some fak blood on the side of your head to simulate and entry wound.)

I havent at all. Explain every single effect in extremely minute detail.

Um, this is Hollywood. Haven't you ever heard of special effects? Jeez!

How does a blank produce blood and brain matter?

That was a blank. I ate your real ammunition.

Tomorrow!

What? When did that happen?

Who's you? Wait, who's me? I dunno anything anymore!

Who?