Rik you are correct partially correct.
the FM 27-10, The laws of land warfare.
“Section III. FORBIDDEN MEANS OF WAGING WARFARE
33. Means of Injuring the Enemy Limited
a. Treaty Provision.
The right of belligerents to adopt means of injuring the enemy is not unlimited. (HR, art. 22.)
b. The means employed are definitely restricted by international declarations and conventions and by the laws and usages of war.
34. Employment of Arms Causing Unnecessary Injury
a. Treaty Provision.
It is especially forbidden * * * to employ arms, projectiles, or material calculated to cause unnecessary suffering. (HR, art. 23, par. (e).)
b. Interpretation. What weapons cause "unnecessary injury" can only be determined in light of the practice of States in refraining from the use of a given weapon because it is believed to have that effect. The prohibition certainly does not extend to the use of explosives contained in artillery projectiles, mines, rockets, or hand grenades. Usage has, however, established the illegality of the use of lances with barbed heads, irregular-shaped bullets, and projectiles filled with glass, the use of any substance on bullets that would tend unnecessarily to inflame a wound inflicted by them, and the scoring of the surface or the filing off of the ends of the hard cases of bullets. “
HR referred to is the annex to the Hague convention No IV, 18 October 1907, embodying the Regulations respect to the Regulations Respecting the Laws of Land warfare.
“The 1949 Geneva Conventions for the Protection of War Victims have been ratified by the United States and came into force for this country on 2 February 1956. The effect of these four conventions upon previous treaties to which the United States is a party is discussed in detail in paragraph 5 of the text. Each of the Hague Conventions of 1899 and 1907 and each of the Geneva Conventions of 1864, 1906, and 1929 will, of course, continue in force as between the United States and such of the other parties to the respective conventions as have not yet ratified or adhered to the later, superseding convention(s) governing the same subject matter. Moreover, even though States may not be parties to, or strictly bound by, the 1907 Hague Conventions and the 1929 Geneva Convention relative to the Treatment of Prisoners of War, the general principles of these conventions have been held declaratory of the customary law of war to which all States are subject. For this reason, the United States has adopted the policy of observing and enforcing the terms of these conventions in so far as they have not been superseded by the 1949 Geneva Conventions which necessarily govern the relations between the parties to the latter (see par. 6 and 7 of the text).”
Although he US never signed the initial accords, by signing off on the latter accords we agreed to the previous. The JAG of the US Army has taken the meaning of intentionally designed to cause more suffering to mean any projectile not purpose built to fragment or mushroom is acceptable. This is because the M852 special purpose ball that uses the 168 gn BTHP is not specially designed to fragment, but is a hollow point. And since M193 and M855 are not designed to fragment but however do, we take it that they are legal under the rules of land warfare.
the FM 27-10, The laws of land warfare.
“Section III. FORBIDDEN MEANS OF WAGING WARFARE
33. Means of Injuring the Enemy Limited
a. Treaty Provision.
The right of belligerents to adopt means of injuring the enemy is not unlimited. (HR, art. 22.)
b. The means employed are definitely restricted by international declarations and conventions and by the laws and usages of war.
34. Employment of Arms Causing Unnecessary Injury
a. Treaty Provision.
It is especially forbidden * * * to employ arms, projectiles, or material calculated to cause unnecessary suffering. (HR, art. 23, par. (e).)
b. Interpretation. What weapons cause "unnecessary injury" can only be determined in light of the practice of States in refraining from the use of a given weapon because it is believed to have that effect. The prohibition certainly does not extend to the use of explosives contained in artillery projectiles, mines, rockets, or hand grenades. Usage has, however, established the illegality of the use of lances with barbed heads, irregular-shaped bullets, and projectiles filled with glass, the use of any substance on bullets that would tend unnecessarily to inflame a wound inflicted by them, and the scoring of the surface or the filing off of the ends of the hard cases of bullets. “
HR referred to is the annex to the Hague convention No IV, 18 October 1907, embodying the Regulations respect to the Regulations Respecting the Laws of Land warfare.
“The 1949 Geneva Conventions for the Protection of War Victims have been ratified by the United States and came into force for this country on 2 February 1956. The effect of these four conventions upon previous treaties to which the United States is a party is discussed in detail in paragraph 5 of the text. Each of the Hague Conventions of 1899 and 1907 and each of the Geneva Conventions of 1864, 1906, and 1929 will, of course, continue in force as between the United States and such of the other parties to the respective conventions as have not yet ratified or adhered to the later, superseding convention(s) governing the same subject matter. Moreover, even though States may not be parties to, or strictly bound by, the 1907 Hague Conventions and the 1929 Geneva Convention relative to the Treatment of Prisoners of War, the general principles of these conventions have been held declaratory of the customary law of war to which all States are subject. For this reason, the United States has adopted the policy of observing and enforcing the terms of these conventions in so far as they have not been superseded by the 1949 Geneva Conventions which necessarily govern the relations between the parties to the latter (see par. 6 and 7 of the text).”
Although he US never signed the initial accords, by signing off on the latter accords we agreed to the previous. The JAG of the US Army has taken the meaning of intentionally designed to cause more suffering to mean any projectile not purpose built to fragment or mushroom is acceptable. This is because the M852 special purpose ball that uses the 168 gn BTHP is not specially designed to fragment, but is a hollow point. And since M193 and M855 are not designed to fragment but however do, we take it that they are legal under the rules of land warfare.