TSA at Washington Dulles International Airport confiscated a SIG 365XL from a Virginia man as he was going through their checkpoint with it in his carry-on bag.
Metropolitan Washington Airports Authority Police were alerted and arrested the man on state charges, and he faces a financial penalty for carrying the gun to a TSA checkpoint.
Bringing weapons to an airport checkpoint carries a federal civil penalty because TSA reserves the right to issue a civil penalty to travelers with guns and/or knives at a checkpoint.
At this point, it is self-explanatory why guns cannot be carried in anything other than a checked bag when flying.
Whether or not someone even has a concealed carry license, firearms cannot be carried directly into the cabin as a traveler.
The rate of guns confiscated each year has increased, albeit with travel decreases during the pandemic.
Although each airline is subject to its own guidelines on traveling with firearms, the main notion is that they should be unloaded and locked in a hard-side case. Also, it is vital to declare them at the check-in counter inside your checked bag or as a checked bag.
Some airlines like to get more info on the firearm itself while others just want to make sure they are properly packaged and then signed for, speaking from personal experience.
Unless you want your Sig 365 with a red dot taken from you at the airport, it would be best to do your due diligence and make sure your luggage is packed with the right belongings.
Something that always helps as well is making sure that if you are a licensed concealed carrier, the state(s) you are traveling to meet the correct reciprocity.