it's worked well for El Al.

One security check point would not allow my harmonicas on-board. No problem. I checked the shoulder bag I used to carry them.

Very very few crimes are commited by legal firearms. Most firearm crimes by far in the US are committed by illegal, oftem stolen weapons.

Firearm regulation varies dramatically from state to state. It may be legal for me to carry a concealed hand gun in Texas, but I would not bring across the state line without knowing the laws of the next state. Massachusetts has mandatory one year prison sentence for anyone being in possession of a firearm that is not registered in that state. Most other states are more liberal.

It is common to have firearms, (most often hunting rifles) on passenger aircraft. They must be shipped in approved firearm cases, inspected, locked.

I am much happier knowing that armed marshalls may be on board my flights.