Abstract: In this paper, analytical solution of time-dependent heat diffusion equation in cylindrical coordinate is derived and solved mathematically for calculating the temperature distribution in thick walled weapon barrel subjected to successive heating and cooling convections and radiations due to continuous firing. The analytical solution has been validated by two numerical models: One is executed by MATLAB to simulate the temperature distribution due to burst fining adopting same assumptions used in analytical model. On other hand, Finite Element model is developed in the environment of ANSYS to solve the problem studying the weight of these assumptions. The results reflect the effect of heat accumulation and the cooling period between two sequential rounds. The temperature-time curves calculated on both inner and outer surfaces of the barrel show good agreement between the analytical and the numerical MATLAB models. However remarkable difference between the F.E.M and the analytical model is presented and discussed.