M256 and specific densities would be needed for each weapon system. In 2013 the Army was developing a new round to replace the M830/M830A1, M1028, and M908. Called the Advanced Multi-Purpose (AMP) round, it will have point detonation, delay, and airburst modes through an ammunition data-link and a multi-mode, programmable fuse in a single munition. Having one round that does the job of four would simplify logistics and be able to be used on a variety of targets. The AMP is to be effective against bunkers, infantry, light armor, and obstacles out to 500 meters, and will be able to breach reinforced concrete walls and defeat ATGM teams from 500 to 2,000 meters. Orbital ATK was awarded a contract to begin the first phase of development for the AMP XM1147 High-Explosive Multi-Purpose with Tracer cartridge in October 2015. In addition to these, the XM1111 (Mid-Range-Munition Chemical Energy) was also in development. The XM1111 was a guided munition using a dual-mode seeker that combined imaging-infrared and semi-active laser guidance. The MRM-CE was selected over the competing MRM-KE, which used a rocket-assisted kinetic energy penetrator. The CE variant was chosen due to its better effects against secondary targets, providing a more versatile weapon. The Army hoped to achieve IOC with the XM1111 by 2013. However, the Mid-Range Munition was cancelled in 2009 along with Future Combat Systems. Secondary The Abrams tank has three machine guns, with an optional fourth: A .50 cal. (12.7 mm) M2HB machine gun in front of the commander's hatch. On the M1 and M1A1, this gun is mounted on the Commander's Weapons Station. This allows the weapon to be aimed and fired from within the tank. Normal combat loadout for the M1A1 is a single 100-round box of ammo at the weapon, and another 900 rounds carried. The later M1A2 variant had a "flex" mount that required the tank commander to expose his or her upper torso in order to fire the weapon. In urban environments in Iraq this was found to be unsafe. With the Common Remote Operated Weapons System (CROWS) add-on kit, an M2A1 .50 Caliber Machine gun, M240, or M249 SAW can be mounted on a CROWS remote weapons platform (similar to the Protector M151 remote weapon station used on the Stryker family of vehicles). Current variants of the Tank Urban Survival Kit (TUSK) on the M1A2 have forgone this, instead adding transparent gun shields