The MA5D, also known as the Insult Rifle bullet hose lesser known as the, okay, I'm about to get super geeky, the Misriah Armory 5th Generation Version D Individual Combat Weapon System (MA5D ICWS) is the latest in the line of the insults to rifles.
While it is the latest in the insults to rifles, the MA5D is not an insult to rifles, infact, it is an awesome beast, but what it lacks is range.
It was made when 343 Industries said "Hey! lets not make the flagship weapon of the series suck this time!", and so the gun was born.
Why? Well, at the end of Halo 3, Chief went into a cryo pod inside the Frigate, where all the Halo 3 versions of UNSC weapons rested, then suddenly, they morph into the upgraded, Halo 4 versions, seriously? That breaks canon entirely, unless they already had that superior technology and figured that they should stick to the outdated shit. But, this seems like an even pettier greivance compared to the fact that the FuD got completely remodelled and became several times larger in the time it was drifting.