Oh, about 2002-2003, they began issuing a magazine of ball and another of HP for USAF aircrew M9s. In the armory, before heading to the jet, we'd load the HP. The thought process was for anti-hijacking, the HP would be more frangible and prevent excessive collateral damage.
The funny part was some of the young pilots actually engaged in discussions about if they were on the ground, in the combat zone, getting attacked at an enroute location, they would have to swap ammo.
