We present the numerical results of both head-on and non-head-on collisions between two stable dissipative optical bullets (DOBs) in a three-dimensional complex Ginzburg-Landau equation with cubic-quintic nonlinearity. The system parameters chosen are in the coexistence regions for both stationary DOBs and double bullet complexes (DBCs). By varying the initial velocities v and the impact parameters P which represent the distance between the parallel trajectories of colliding bullets, we observe three generic properties of the bullets: fusion, fission, and quasi-elastic collisions. A novel and interesting behavior is observed in the results, in which two or three DBCs occur in non-head-on collisions at intermediate values of v.