A method for making high energy compositions, such as propellants, explosives, pyrotechnics or the like, including a solid metal particulate fuel dispersed in a cured binder matrix. The compositions are formed with ingredients including a particulate metal fuel such as boron, binder polymer (such as GAP polyol), binder plasticizer, and a curing agent containing isocyanate. The improved method includes pre-reacting the particulate metal fuel with an amount of isocyanate, which acts as a curative to neutralize residual acid. The particulate metal fuel/isocyanate from the pre-curing step is mixed together with the binder polymer, binder plasticizer, and remaining curing agent to form the solid propellant. The initial neutralization of the metal fuel avoids gassing and improves the mechanical properties of the propellant yield.