If you're flying within the USA, and you own a firearm, there is a solution to provide some extra security.
As Deviant Ollam explains, if you have a firearm in your checked luggage, you need to have it in a hardcase, locked with a non-TSA lock. The idea is likely having a small handgun case in a larger bag, but nothing precludes you from having a large case as your checked luggage, that just happens to have your gun in it.
You need to declare your firearm when checking your luggage, fill in a form, show your firearm to be unloaded, have your luggage screened while you're present, then lock it. And that's it. You have to keep the keys to that lock on your person.
As Deviant explains, even a starter pistol counts as a firearm for the TSA. On Deviant's site you can read many accounts of people who have flown like this.