So this morning I have to visit the courthouse to support my wife at a case. So as is required, I disarm in the car and head on in. What I forgot was that when I emptied my pockets for the metal detectors that I was going to drop a speed loader with 357 mag hollow points into the bucket.
Fortunately, as soon as I did I pointed it out to the operator. There was first a look

but then she took a closer look and said, oh, we can just check that. And your little pocketknife too. They ran it through the metal detector where it was picked up by another person. They first yelled to the second that they would have a check in. She looked at it with more shock

but then asked for my name. I gave her only my first name and she picked up a baggie and a ticket. She handed me one and then put the other in the baggie.
Seemed like they knew what to do but it happens pretty infrequently. I'll see how it goes when I pick up on the way out. Sure wish I could check my weapon into a locker instead of leaving it in the car.
So it seems reasonably efficient if you carry your spare mag into a courthouse. I'm pleased by the folks here :-).