[Brian Pfleuger]

Technically, there are several different ideas and misconceptions in this thread.

Many people confuse the general baggage rules with the rules regarding bags containing properly declared firearms.

"Ordinary" bags may be opened at any time that a TSA officer deems it necessary. "Necessary" is not arbitrary and is defined, rather tightly, by the Standard Operating Procedures. Bags containing properly checked firearms have their own set of rules.

There are at least 2 options for the airports screening of checked bags. Small airports often check ALL bags by hand. The rules require all passengers checking a firearm at such an airport to be present at the time of screening. Once the bag is screened and re-locked, it should make it's way directly to the aircraft as there in no further type of screening at these airports. Larger/busier airports mostly have semi-automated x-ray machines than screen checked bags. The passenger is still supposed to be present so that the legality and packing of the firearm can be verified. After that, the bag is screened like any other bag and will be opened like any other bag if there is a reason to believe it contains serious prohibited items (IE, possible bomb/unknown suspicious contents). There are specific protocol in place when a bag containing a gun needs to be opened at these airports (such as LE present) but it should be a rather rare event and if it's highly suspected to be a bomb, the opening method will likely be high explosives.