I always go an hour earlier when traveling with a firearm. For instance, here at Washington Dulles, I would show up at 3:00 pm for a 6:00 pm takeoff. You will go to the airline counter first where the ticket agent will give you a card to sign and to slip into your gun case which declares the weapon unloaded. You need to tell the agent which bag also contains your ammunition. An agent will then escort you to a TSA manned x-ray machine where your bags will be x-rayed, stamped, and sent on to the aircraft. This can be five minutes or twenty-five depending upon the line and whether or not TSA looks at the weapon or the ammo. In probably a dozen flights over the last several years, I have always found the TSA folks to be couteous and reasonable. I should note, I go to every effort to be polite to them.