An analysis has been performed to investigate the ballistic performance of the 155mm K307 extended range projectile provided with base bleed unit. Different tools were used to perform this analysis; including analytical modeling and available computational resources. Drag reduction modeling has been used to study the effect of different parameters on base bleed performance such as burning rate, number of base bleed grain parts and the grain dimensions. The study has showed that a better ballistic performance could be obtained when the exit mass flow rate of the burnt gases is relatively large at the first few seconds of the projectile flight. To change this mass flow rate along the trajectory, a newly developed technique has been introduced. The technique depends on filling the base bleed unit with a grain subjected to burning by two rates resulting in extending the projectile range.