Anytime you fly it’s a good idea to check all your baggage. My carryon gets a thorough look. Even my turkey vest which is checked baggage is thoroughly emptied and checked. All ammo, guns, and knives go in the locked gun case. Ammo is in boxes and I tape them and save empties to put back in the box for the return flight so if checked, they don’t shake as having loose ammo.
I can’t believe TSA missed it. Heck I have a locked gun case and every trip I don’t have locks when landing and a note that says they had reason to suspect a weapon. I’m like, duh, it’s a locked gun case and the declared paperwork is inside. And I have to buy new locks no matter where I land even though my locks are TSA approved and make my departing airport unlock them with their key!! Instead of unlocking them, they cut them.