The invention relates to Insensitive Munition (IM) energetic materials particularly non-phthalate IM propellant compositions.An energetic composition suitable for use as a propellant comprises the following components in the following relative proportions: component A; from 60% to 90% by weight of a highly energetic filler comprising at least one nitramine compound; and component B: from 5% to 20% by weight of a binder, component C: from and 3% to 15% of a plasticiser wherein the plasticiser comprises formula (A) of from 1% to 9% by weight, wherein Formula (A) is a diester plasticiser of R1—OC(O)—R3—C(O)O—R2,  Formula (A) wherein R1, R2, and R3 are independently selected from C3 to C10 alkyl or alkenyl. the percentages by weight of components A, B and C, together with minor additives, if any, adding to 100%.