A computational study is performed to predict the drag reduction for a base bleed projectile. 2-D and 3-D simulations are conducted to describe the flow past a projectile with base bleed. The calculated computational results are compared with measurements of total drag coefficients based on published results for 155mm K307 projectiles with live/dummy base bleed grain. In addition, the mean drag coefficient measurements based on live firing tests for a five K307 projectiles with live BB grain at different Mach numbers are used to validate results obtained from the computational results. Differences between the drag coefficient calculated from computational and published live firing measurements of the drag coefficient for K307 are less than 5.2% and 6.8% for projectile with dummy and live BB, respectively. On the other hand, the maximum deviation between computational results and real measurements from the live firing tests of live BB projectiles is 2.75%.