MA5D assault rifle

The Individual Combat Weapon System, Caliber 7.62 mm, MA5D, more commonly known as the MA5D Individual Combat Weapon System, MA5D ICWS, or simply as the MA5D assault rifle, was a selective-fire bullpup assault rifle used by the  during the  and. In 2554, as part of post-war UNSC equipment consolidation efforts, the MA5D was adopted as the standard-issue service rifle of all branches of the UNSC military, and all other MA5 variants began to be phased out of service.

Development & Service History
The MA5D began its service life as the MA5-2, an experimental upgrade of the, adapting many features introduced by the newer MA5B onto the MA5, such as a weather-resistant outer casing and internal mounting system, while also sporting a longer, heavier barrel and more ergonomically-placed controls. This was an attempt to convince the and  to upgrade from the MA5 (or MA37 as the Army called it) to a more modern weapon system. Unfortunately, this effort backfired, producing a weapon even more expensive than the MA5B, thus turning away the interest of both branches. Still, the was intrigued by the design, and in 2523 they ordered a modest quantity of the weapons to bolster their armories with.

The Marine Corps was pleased with the new weapon, and while it was not willing to replace their still relatively new MA5B arsenal with it, they did keep on procuring the weapon in quantities large enough for to justify keeping the weapon in production.

Mariah continued tweaking the weapon over the course of the Human-Covenant War, and in 2546, the MA5-2 would compete against a new design, the XMA5-3, for a chance to be phased in as a replacement for the MA5B in the Marine Corps and. However, the MA5-2 would lose to the cheaper XMA5-3. The XMA5-3 would be introduced to the Marines and Navy as the MA5C starting in 2549, and in response, Misriah rechristened the MA5-2 as the MA5D. And despite their recent switch to the MA5C, the Marines kept on purchasing small numbers of the weapon just as they had done previously.

Following the end of the war in 2553, the UNSC began to make efforts to rapidly rebuild and reorganize itself to better respond to external threats in the future. Part of this effort included standardizing weapons across all branches of the military, in order to ensure that UNSC troops possessed the same standard of equipment throughout space. When it came to the MA5 series, UNSC officials were torn as to whether to keep fielding the MA5C or to procure a new MA5 rifle, and so in an effort to try and solve this dilemma, thorough testing was conducted to decide which existing MA5 rifle presented the best combination of versatility, reliability, and stopping power, and whether or not any of the models possessed what the UNSC considered to be adequate marks in each category going forward. It was presumed by nearly all that the MA5C would perform best, and by some that none of the rifles would meet the new performance requirements the UNSC had put forward. However, when the results came back in early 2554, they were a surprise to all except officials of Misriah Armory: the MA5D was the only MA5 rifle to not only meet the UNSC's new requirements, but to exceed all of them.

With the MA5D standing out as the clear choice to phase in as the standard rifle of the UNSC military across all branches, all existing orders for the MA5, MA5B, and MA5C were cancelled, and a massive procurement order for the MA5D was placed in March of 2554. The first units to receive the new MA5Ds were those stationed aboard the recently-commissioned UNSC Infinity, followed by those of the newly-formed.

As of 2558, the MA5D remains the standard service rifle across all branches of the UNSC armed forces.

Design Details
The MA5D effectively combines the best of all three other MA5 variants: the versatility of the MA5, the raw stopping power of the MA5B, and the accuracy and controllability of the MA5C. It sports a longer barrel than both the MA5 and MA5B, with a one-in-twelve barrel twist. The end of the barrel is threaded to allow for attachment of suppressors and muzzle brakes, with a flash suppressor equipped on the stock version of the weapon. The MA5D possesses a rate of fire of roughly 600 rounds per minute, higher than the MA5, but less than the MA5B and MA5C, but with a greater muzzle velocity and thus greater muzzle energy than all other MA5 variants. It is slightly more accurate than the MA5C, with a approximate accuracy of 7.36 minute of arc, making it capable of, under controlled conditions, shooting roughly seven and a half inch groups at 100 yards.