When I was in high school I took a summer job at the Fleet Post office. We sorted mail, and parcels to be sent to naval personnel aboard ships. A lot of guns were shipped to officers that wanted something besides standard issue. mostly 357 magnums. The FBI had one way mirrors on the walls surrounding the work area. They would come unannounced and watch us. We never knew if they were there or not. I imagine it's similar at the mint.
Oh, like shipping to the APO's?! It was probably postal inspectors not FBI but I get your point. I would say, stealing (and getting caught) might get someone fired.