High Quality Content by WIKIPEDIA articles! The XM-736 8-inch projectile was a binary howitzer round that was designed to carry the nerve agent VX. After the suspension of the testing in 1982, models indicated the the shell could be unstable in flight due to the liquid properties of VX. However, instabilities were not observed during earlier testing, and it is unknown if instabilities in the shell were ever found. Binary chemical weapons or munitions are chemical weapons wherein the toxic agent is not contained within the weapon in its active state, but in the form of two chemical precursors, physically separated within the weapon. The precursors are designed to be significantly less toxic than the agent they make when mixed, and this allows the weapon to be transported and stored more safely than otherwise.