I love the word: Pistol
Not gun, not firearm. not glock (I don't know how to spell that because I am not a gantsta and they don't know how to spell...so really: is there a proper spelling?)
Imagine...you are threatened in some manner and you raise one eye brow and look your attacker in the eye and say:
"I'll have you know....I am carrying a pistol"
This dignified approach will set the assaulter on their heels, especially if done in an English accent.
Let me tell you, not from experience but the experience in my fantasy world, this is an efficient way to ward off a mugger.
If you just yelled "I HAVE A GUN" you will get the beat down or your face blown off.
BUT..."I'll have you know .... I am carrying a pistol" is pure gold. The attacker will for that split second be trying to figure out what a pistol is, as he is familiar with gun, heat, glock, uzzie, assault rifle, etc...really I have no idea what hood talk is for gun.
This gives you just enough time to pull out your pistol or deliver a nice hard elbow to the face or fingers in the eyes.
"Don't make me get out my bayonet" would also work in this situation.