Myself was surprised when my carry on went through the x-ray machine and they curiously looked at it few times. they pulled it off the line and fumbled around then the agent pulled out a loaded .380 magazine much to my surprise. They looked at me I looked at them and thought oh shit, they're going to strip search me then who knows what else.
They asked why it was there and did I have the gun it went to. I explained as I drove to FL I separated my magazine from my firearm going through non-recipratory states and left the magazzine in my suitcase. No I did not have the gun.
Honestly this is where things got weird. They confiscated the magazine and ammunition but returned my leather mag holder. They ran my drivers license, asked a few questions about small towns in my area that only a local would know. This all took about 5 minutes. I was told I would receive a letter and not to ignore it. I was at my gate and headed home.
All in all I was surprised and impressed with the experience (not what everyone was expecting I know). Six months later I received a letter from TSA giving me a list of prohibited items and a warning.
I then applied for pre-check and received it which I was doubtful about qualifying for... go figure