A Note About "Open Tipped Ammunition"
Some people claim that the use of "hollow point" or expanding bullets is illegal in warfare under the Geneva Convention (which is a set of international agreements to provide for "civilized" behavior between nations at war). The topic was actually addressed by the Hague Accords of 1899 and 1907 and proscribed the use of "arms, projectiles, or material of a nature to cause superfluous injury" (or in some documents "unnecessary suffering") and neither term is defined. By the way the conventions only apply to a declared war against national enemies by signatory parties. The US is not a signatory of this convention, but does abide by it.
In regards to the use of "open tip match" bullets which provide increased accuracy and which are not specifically designed to expand, the Hague Convention IV of 1907 (and NOT the Geneva Convention) does not proscribe them, nor bullets which yaw and fragment in tissue. This position was not disputed by the 1978 UNCCW Conference and was reconfirmed during its’ review in 1994 - 1996. Thus the US Judge Advocate General office's 1990 decision to authorized certain OTM projectiles, which yaw and then fragment just like many FMJ bullets, for unrestricted land warfare use is perfectly legal under international law and neither the nannie-state UN nor any other organization have any grounds to protest their use.
OTM ammunition is currently not more frequently used in 5.56 (as the Mk262 77 gr OTM) because it is not as widely available via the supply system and is substantially more expensive than M855, but there is a definite push to use it in all calibers., including the 7.62 NATO. The issue ball round in 6.8 x 43 (6.8 SPC) is the 115 gr Sierra MatchKing "enhanced fragmentation" bullet.
If one wanted to get technical about this issue there is really no basic for proscribing a bullet that does expand, since: a) there is nothing about them that causes "unnecessary suffering; and b) an expanding bullet is simply an attempt to make a small diameter bullet create a wound channel that a larger diameter non-expanding bullet would, and most "expanding bullets create a less messy wound then fragmenting bullets do. In actuality this so-called "ban" is very misleading for while expanding projectiles may supposedly be proscribed, the use of mines, explosives, fragmentation, and flame weapons which indiscriminately shred and maim their victims are not.