Assault rifle

An Assault Rifle is a selective-fire firearm using a projectile with a muzzle energy in between those of a full-sized rifle and a smaller submachine-gun or a pistol. Assault rifles are categorized in between battle rifles, which fire a full-sized rifle cartridge, and submachine guns, which fire a pistol cartridge rather than a rifle cartridge. Examples of assault rifles include the M16, AK family, G36, FN FNC, and the Steyr AUG.

History
Assault Rifles date back to the end of the Second World War. Germany developed the first assault rifle, a weapon called the Sturmgewehr 1944. Although it was not fielded in the same quantities as the Maschinenpistole 1940 or the Karabiner 98Kurz, the devastating losses it inflicted upon the advancing Soviet armies encouraged the USSR to develop this new class of weapons. The result was the Russian AK-47, which basically set the definition of an assault rifle.

Small arms technology including the assault rifle can be described as a mature technology. However, changes in the battlefield realities throughout the 21st century lead to technological changes and directions such as armour piercing or saboted sub-calibre tungsten darts, more powerful cartridges, application of new composite materials such as carbon fibre or carbon nanotubes, and use of exotic metals such as titanium and scandium]. As weapons evolved, the delicate balance for assault rifle systems between power, weight, recoil and terminal effects continueally shifted in an attempt to defeat body armour, to match the range of full-power cartridges, and to penetrate through wind shields and thin-skinned vehicles while still producing good terminal effects. As personal body armour technology improved throughout the century, for example from the development of magnetorheological fluid-based smart materials, assault rifle designs were constantly forced to adapt in order to remain effective. The changes in assault rifle technology come from the maturation of other fields (as camera technology become more advanced, cameras were integrated into rifles) and much research and development were put into integration of rifles with advanced electronics. By the time of the Halo trilogy, most assault rifles also house an onboard electronics suite, showing ammo capacity, a compass, and other information, without the use of a HUD.

The future of the assault rifle may not be entirely in the design of the firearm itself, but rather in the ammunition it fires. Reducing weight and cost being one of the original reasons for the development of the intermediate powered round and subsequently the assault rifle, that goal has been taken to a whole new level with the development of caseless ammunition which does away with the weight and cost of shell casings.

These could refer to the following:
 * MA3 Assault Rifle - The predecessor to the MA5 series rifles.
 * MA5 Series
 * MA37 Individual Combat Weapon System - The original MA5 (known as the MA37 for the UNSC Army) introduced in 2437. It was used by the UNSC Army up to as late as the Battle of Reach. (Halo: Reach)
 * MA5B Individual Combat Weapon System - The standard UNSC Navy and Marine Corps armament from the early-2500's to 2552. It was phased out shortly after the Battle of Reach and the Battle of Installation 04. (Halo: Combat Evolved)
 * MA2B Assault Rifle - The stripped-down version of the MA5B Assault Rifle.
 * MA5K Carbine - A carbine variant in the MA5 series utilized by the SPARTAN-III's and other Special Operation forces.
 * MA5C Individual Combat Weapon System - A new MA5 model introduced in late-2552 during the late Battle of Earth and the Battle of Installation 00. (Halo 3, Halo 3: ODST)