Free-streaming ejecta velocity vs. mass above for all models: 0.6 + 0.2, 0.6 + 0.3, 1.0 + 0.05, 1.0 + 0.1, 1.2 + 0.02, and 1.2 + 0.05  M _☉. Core masses are as labeled; black, red, and blue lines are for core masses of 0.6, 1.0, and 1.2  M _☉, respectively. The solid lines are the smaller envelope masses for each model, and the dashed lines are the larger envelope masses. The velocities shown are calculated by taking the velocities 100 s after shock breakout and subtracting the effect of leaving the gravitational potential wells.