MA5B assault rifle

The MA5B Individual Combat Weapon System was an assault rifle used by the UNSC Marine Corps and Navy throughout most of the Human-Covenant War. It was easily one of the most recognizable and pervasive infantry weapons fielded by the UNSC during conflict with the, if not the most. The MA5B perfected and refined the defining features of the rifles introduced by the original MA5, such as the electronic ammunition counter and electronics suite, while also introducing new features like internal attachments and a larger, redesigned magazine. The massive success of the MA5B would lead to an even more successful weapon which debuted at the very end of the war: the MA5C.

Developement
The MA5B ICWS was commissioned by the UNSC just following the in the, which included the uprising that resulted in the  in 2492, and the  in 2494. Fearing the worst, the UNSC commissioned a number of weapons in order to update its aging arsenal in preparation for the possibility of civil war.

Misriah Armory and a handful of other weapons designers quickly churned out a number of prototype weapons. While most were quickly turned down, there were several that showed promise, including XM392A2, The XM55, the XMA25A1, the XM90A and the XSRS Series 2. The XMA25A1 proved to be a hit amongst the marines who demonstrated the weapons, but most stated they disliked the designation, which they found to be a mouthful. Misriah Armory responded to this by making the decision to redesignate the rifle the XMA5B, and similarly renamed the XM55 the as well.

The newly christened XMA5B was a heavily revamped version of Misriah's MA5 assault rifle that was adopted by the in 2437. The weapon built further upon the principles that led to the success of the original MA5; ruggedness, versatility, and vicious medium-to-close-range firepower. Thanks to remarkably few setbacks in the rest of the development process, the finalized model of the XMA5B, now the MA5B Individual Combat Weapon System, was finished in record time, and in 2506 the UNSC Marine Corps adopted the MA5B to replace the MA5 as their primary service rifle, with the UNSC Navy following suit in 2514. however, the and  opted to keep fielding the original MA5 (known as the MA37 by the Army), since it was cheaper, still highly effective, and still receiving ongoing manufacturer support from Misriah.

Design Details
The MA5B was a marked improvement over the original MA5 rifle. The operation of the weapon was almost the same as the original MA5, though the reloading and locking process was made faster and more efficient, allowing for increased rate of fire, and the rifle was given very slight sound-suppressing properties to decrease the volume of the sound made when firing the weapon. The latter change was made to prevent the chances of the weapon's operator from suffering hearing loss, which was a relatively common issue with the original MA5, as it was exceptionally loud. Unfortunately, Misriah overlooked one major issue with the MA5: suboptimal barrel twist. The barrel twist was 1 in 5.75, which was a poor choice for the weapon's caliber, as most other 7.62x51mm weapons used at least a 1 in 10 twist. This resulted in the weapon being highly inaccurate at longer ranges.

The MA5B also featured a lightweight weather-resistant casing made from a stamped aluminum-based alloy and a heavy-duty plastic polymer. Another new feature was an internal attachment system; the heavy duty flashlight below the barrel could be removed and attachments such as underslung shotguns or grenade launchers could be affixed to the inside of the weapon, and could be done so with little difficulty and even in the field thanks to a small field-stripping toolkit located within the front end of the barrel shroud.

The electronics suite of the MA5B, unlike most UNSC weapons, included much more than just a wireless uplink that uploaded an aiming reticle into the user's vision via or into any visual displays that the operator may have been equipped with, but it also included an integrated ammunition counter, digital clock (which synchronized with the operator's neural interface upon activation of the weapon's electronics to ensure accuracy, and could be set to synchronize with other equipment the operator may possess if they did not have a neural interface or if their nueral interface was not properly functioning), and a rudimentary digital compass. The weapon also featured retractable iron sights for use by non-UNSC users, who may lack a device to upload a reticle into.

Advantages
The MA5B was an incredibly effective weapon against the Insurrectionists. Its brutal firepower and vicious rate of fire could tear through moderately armored targets in a matter of seconds, and its 60 round magazine meant that numerous enemies could be neutralized on a single reload.

Against Covenant troops, the MA5B was less effective, but it still performed quite admirably. Unshielded foes like or  were easily shredded by the hail of bullets that the MA5B was capable of unleashing. However, Covenant troops equipped with like  could often shake off fire taken from an MA5B at range without trouble, so weapons like the  or the  were considered more ideal for engaging shielded enemies due to their superior accuracy. But the MA5B was found to be surprisingly accurate when fired in short, controlled bursts, and quickly developed a simple method to effectively engage Elites with the MA5B at most ranges: "pulsing" the trigger to release quick, accurate bursts of fire while drawing in closer to the alien, then opening up with fully automatic fire once up close, as an Elite's energy shielding usually could not withstand more than a few short moments of continuous close-range fire from the MA5B.

The MA5B's relatively poor performance against shielded targets at range would continue to be an issue throughout the Human-Covenant War, but the SPARTANs' method of dealing with the issue became adopted as the standard tactic for engaging shielded enemies with the MA5B, and additional tactics for engaging shielded foes effectively with the weapon were developed over time as well.

In situations in which accuracy was secondary to rate of fire, the MA5B was second to none. Even the paled in comparison to the MA5B, as the M7's greater rate of fire was over shadowed by the MA5B's more manageable recoil and greater stopping power.