The MA5C Assault Rifle is the new usable assault rifle in Halo 3. More accurate, powerful, and generally worthwhile and realistic than the piece of shit SMG Act-Alike it replaced. A smaller magazine (from a lonely press in a rural area) and lower fire rate were traded for this improvement, but at least you are now capable of killing n00bs with it, instead of having to use an AR as a last resort when you can't find the Ass raper 9000.