Template:Weapon The MA2B Assault Rifle is a cut-down version of the standard MA5B Assault Rifle. The MA2B is tough and reliable. It has electric targeting, an ammo supply indicator, and a recoil-reduction system. The MA2B can deliver an impressive fifteen rounds per second and uses .390 caliber ammunition. The Spartans used these weapons periodically in the books when they wanted to have very little ordanance for a mission. In fact, John used an MA2B assault rifle on his very first real mission. They used these rifles first when capturing Colonel Robert Watts of the Eridanus Rebels.