I pulled out my gun when I walked into the bank
I can't believe you would do such a dangerous thing. What did you say as you pulled out your gun at a bank?
"I will blow your fucking brains out if you don't give me all your money in the cashier-section. I want 100.000 in cash. NOW!"
Robbing a bank with a gun is immoral. It's also a crime and you'll be caught and severely punished after they track the money.
What's wrong with this? It's really an efficient way to get money from the bank.
Someone could get hurt including yourself. If that gun goes off or the police sees you with a gun they will shoot you.