If you are not being threatened with violence then pointing a gun at the other person would constitute assault with a deadly weapon (felony) and brandishing a firearm. If you didn't have a concealed carry permit, you would also be guilty of carrying without a permit (first offense misdemeanor or felony, second offense felony). You would be arrested, lose your gun, go to jail, probably for more than a year, and lose your right to keep and bear arms. Exact penalty would depend on plea bargaining, the quality of your attorney and what the judge had for breakfast.
Some fool starts yelling at you after a fender bender and you pull out your glock and he calls the cops it will probably be assault with a deadly weapon.