Let's understand something about the terms "AP" and "armor piercing" ammo. In the military lexicon I believe the term means specially hardened or explosive projectiles designed to pierce hardened armor found on tanks and the like. Am I wrong, Travis? You would know better than I.
When used by a politician or a media talking-head it is simply a weasel-word synonymous with "cop-killer bullet." That loosly means any projectile capable of piercing body-armor like a kevlar vest aka "soft-armor." Any high power rifle cartridge is capable of pushing its projectile, be it full-metal-jacket, soft-nose or hollow-point, through the toughest body-armor available with lethal power. That would include virtually every hunting round in existence. Don't get hung up on the word 'rifle' either; their are numerous pistols chambered in these cartridges as well.
The point being; any 'ammo' capable of efficiently killing any game animal bigger than a fallow deer is capable of piercing soft-armor.
I haven't read the article or fully read the thread but if the issue at hand comes down to only a study of AP ammo then one needs to ask themselves a couple of questions. Such as: "Who will actually conduct the study?" "What will be the guiding focus of the study?" "What will the gov. do with the results of the study?" Does anyone really think the Gov. is going to fund a study merely to find out the penetration power of various chamberings and bullet combinations? Gun writers, not to mention the firearms industry itself, have done the subject to death.
spodefly, if the intention of the study is to identify ammunition that can kill through body-armor then you can bet the farm the purpose of doing that is to lend credence to legislative efforts to restricting said ammunition. Once the study is done and the results have been handed to the media regarding "cop-killer" bullets the momentum will have already carried us across the Rubicon and the bridge will be ready to torch.
The bridge is already burning!