M634 Experimental High-Powered Semi-Armor-Piercing

An M634 9.5×40mm KURZ from The Art of Halo 3.

M634 Experimental High-Powered Semi-Armor-Piercing, abbreviated as M634 X-HP-SAP or M634 9.5×40mm HP-SAP, and also known as the 9.5×40mm KURZ, is a 9.5×40mm rifle cartridge made specifically for the BR55, the BR75, and the BR85 series.

Overview

The M634 X-HP-SAP was developed in conjunction with the prototype XBR55 Battle Rifle. As an experimental round, its use is only limited to the BR55 Battle Rifle, the BR55 Heavy Barrel Service Rifle, the BR75 Battle Rifle, and the BR85 Heavy Barrel Service Rifle. While the round was designated as experimental around 2525, at some point between then and 2558, the "experimental" designation was dropped, becoming the M634 9.5×40mm HP-SAP.

Properties

As designated in its name, the M634 X-HP-SAP is an experimental round. It uses a special propellant that allows it to achieve a higher muzzle velocity than the M118 7.62×51mm round while using a smaller cartridge. It is also semi-armor-piercing, meaning that it mixes the properties of an armor piercing round with the properties of another type of round. The second type is unknown, though it is most likely similar to the M225 SAP-HE used in the M6 Series.

Unlike most ammunition types in the Halo games, this is not a real-life ammo type, the closest comparison being the 9×39mm special purpose round, also known as the “Kurz.” Designed in the Soviet Union, this round was designed to defeat lighter body armours, while being subsonic to maximize stealth potential; it appears most real-life weapons firing the bullet have integrated silencers. However, the M634 does not appear to be subsonic, as it produces a super-sonic “crack” or “whip” when fired, and is instead intended for high-velocity and long-range marksmanship.

The M634 is likely the result of human inclinations towards increased size (leading to the 9.5 mm bullet) and technological manipulation (leading to the experimental propellant). It's also possible the large caliber, while overkill by current standards, is required to defeat the advanced body armor of the Insurrectionists, and later, the Covenant. Additionally, the round is very similar in dimensions to the .375 SOCOM round, which came out after the battle rifle first premiered in Halo 2, but shares its 9.5×40mm cartridge measurements. At some point before 2558, the experimental identification of the M634 was removed, suggesting the round received formal adoption by the United Nations Space Command. In real life, the round would likely be subsonic, with a poor ballistic profile, akin to the Soviet 9x39mm round used in the VSS Vintorez platform. While this round is ideal for subsonic applications (use with an integral suppressor) it would be an exceedingly poor choice for its role in the Halo universe (as a standard cartridge) as portrayed in Halo 2, 3, 4, and Reach, due to its poor velocity and total lack of armor piercing capabilities. Additionally, the term "Kurz" applied to the round is highly confusing, as this term was rarely used in history to denote a round that had a cartridge that was shortened from a standard military round, within a German military application. The term is then likely applied erroneously to the 9.5x40mm round, since there is no indication that the 9.5x40mm round is a "shortened" version of an existing UNSC standard issue military cartridge.

Gallery

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  A 9.5×40mm cartridge in a magazine used to feed the BR55 service rifle in Halo 2: Anniversary multiplayer.

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  Spent 9.5×40mm casings ejecting from a BR55 in Halo 2: Anniversary multiplayer.

List of appearances

• Halo: First Strike (First appearance)
• Halo 2
• Halo 3
• Halo: Evolutions - Essential Tales of the Halo Universe
• Halo 4
  • Spartan Ops
• Halo: Spartan Assault
• Halo: Escalation
• Halo 2: Anniversary
• Halo 5: Guardians
• Halo Infinite