[Buzzcook]

There's been a couple threads that reference the Hague Convention. I thought posting the text of the section in question might clear some things up.

The basic reasoning behind the ban on expanding bullets is in the Declaration of St. Petersburg; November 29 1868
http://avalon.law.yale.edu/19th_century/decpeter.asp

Considering that the progress of civilization should have the effect of alleviating as much as possible the calamities of war:

That the only legitimate object which States should endeavour to accomplish during war is to weaken the military forges of the enemy;

That for this purpose it is sufficient to disable the greatest possible number of men;

That this object would be exceeded by the employment of arms which uselessly aggravate the sufferings of disabled men, or render their death inevitable;

That the employment of such arms would, therefore, be contrary to the laws of humanity;

http://avalon.law.yale.edu/19th_century/dec99-03.asp

Laws of War :
Declaration on the Use of Bullets Which Expand or Flatten Easily in the Human Body; July 29, 1899

The Undersigned, Plenipotentiaries of the Powers represented at the International Peace Conference at The Hague, duly authorized to that effect by their Governments,

Inspired by the sentiments which found expression in the Declaration of St. Petersburg of the 29th November (11th December), 1868,

Declare as follows:

The Contracting Parties agree to abstain from the use of bullets which expand or flatten easily in the human body, such as bullets with a hard envelope which does not entirely cover the core, or is pierced with incisions.

The present Declaration is only binding for the Contracting Powers in the case of a war between two or more of them.

It shall cease to be binding from the time when, in a war between the Contracting Parties, one of the belligerents is joined by a non-Contracting Power.

The present Declaration shall be ratified as soon as possible.

The ratification shall be deposited at The Hague.

A proces-verbal shall be drawn up on the receipt of each ratification, a copy of which, duly certified, shall be sent through the diplomatic channel to all the Contracting Powers.

The non-Signatory Powers may adhere to the present Declaration. For this purpose they must make their adhesion known to the Contracting Powers by means of a written notification addressed to the Netherlands Government, and by it communicated to all the other Contracting Powers.

In the event of one of the High Contracting Parties denouncing the present Declaration, such denunciation shall not take effect until a year after the notification made in writing to the Netherlands Government, and forthwith communicated by it to all the other Contracting Powers.

This denunciation shall only affect the notifying Power.

In faith of which the Plenipotentiaries have signed the present Declaration, and have affixed their seals thereto.

Done at The Hague the 29th July, 1899, in a single copy, which shall be kept in the archives of the Netherlands Government, and of which copies, duly certified, shall be sent through the diplomatic channel to the Contracting Powers.

So there ya go.