M634 Experimental High-Powered Semi-Armor-Piercing

M634 Experimental High-Powered Semi-Armor-Piercing (M634 X-HP-SAP or 9.5x40mm KURZKurz is a German word for "short".) ammunition is a type of UNSC experimental round that is made specifically for the BR55 Battle Rifle series. The round's metric dimensions are 9.5x40mm, which is slightly larger compared to the M118 FMJ-AP rounds used in the MA5 Series assault rifle. and was introduced into the UNSC Marine Corps along with the prototype XBR55 Battle Rifle around 2525. At some point before 2558, the experimental identification of the M634 was removed, suggesting the round received formal adoption by the UNSC.
In combination with the BR55 Battle Rifle, this round is accurate enough that the 2x scope on the Battle Rifle is useful. Even when fired in three-shot bursts, the round produces little recoil resulting in very little muzzle lift. it is more effective against both shielded and unshielded Covenant personnel than the M118 FMJ-AP , as the increased accuracy leads to an increased number of headshots, and the increased kinetic energy of the round leads to faster shield depletion and increased damage to unshielded enemies. It has been shown that a BR55 Service Rifle with M634 ammunition does enough damage to kill an opponent faster than an MA5C Assault rifle using M118 FMJ-AP ammunition. Overall, the M634 X-HP-SAP round provides good accuracy, controllability, and effectiveness against all personnel.
However, while the M634 X-HP-SAP does do more damage than the M118 FMJ-AP against vehicles, it is still not a very effective round at damaging or stopping vehicles.
The M634 uses a special propellant that allows it to achieve a higher muzzle velocity than the M118 FMJ-AP. It is also semi-armor-piercing due to the larger caliber similar to the M228 SAP-HP used in the M6 Series.
The closest real-life counterpart of this round being the .375 SOCOM, which is a sized down version of the .458 SOCOM, a cartridge designed in 2000. However, the .375 SOCOM was designed in 2013 after the battle rifle first premiered in Halo 2, and interestingly shares its 9.5×40mm cartridge measurements.
==Appearances==
*Halo: First Strike
*Halo 2
**Halo 2: Anniversary
*Halo 3
*Halo: Evolutions - Essential Tales of the Halo Universe
Category:UNSC Ammunition