Print out the rules of transporting a firearm from both the airlines website, and the TSA. Carry the printouts with you, in case the ticketer is unaware. I flew Southwest to FL. I had the slide locked to the rear, mag out, and placed the cable lock through the gun. Placed this locked gun and two loaded mags in a lockbox. I declared I had packed a "unloaded, locked firearm", being careful to not use the words "I have a gun". She asked to see it, and I moved the lockbox to the top of the suitcase, but still inside. I opened it so that she could see it, but not people behind me. We filled out a tag which went in the lockbox, and that was it. Flying is not generally a problem if you follow the rules. Please read the rules, as they've probably changed since I last did this. I don't remember if there is an ammo limit.