Gun propellants ana double base rocket propellant were tested to find out stabilizer consumption and molar mass degradation between 60 degree Celsius and 90 degree Celsius, in part between 40 degree Celsius and 110 degree Celsius. The stabilizer content was measured by reversed-phase high performance liquid chromatography (HPLC) with UV-detection, and the molar mass degradation by gel permeation chromatography (GPC) with refractive index detection. For the evaluation of the experimental data, different kinetic models were used. Molar mass decrease is described by a model based on statistical chain scission by the decomposition of chain elements. Stabilizer decrease is described with two models, one based on a first order reaction, the other is a combination of first and zero order reactions. Two temperature regions with different activation energies were found for the two investigated properties, stabilizer consumption and molar mass decrease, in the single base gun propellant A5020. T he transition is about at 60 degree Celsius to 70 degree Celsius. This influences clearly the prediction of lifetimes. The Arrhenius parameters of the two reaction regions of both properties have been determined. The resulting lifetimes are discussed.