Shot placement is more important than bullet construction, that and some times animals just don't want to die quickly.

My cow moose last fall at ~150 yds dropped at the shot and didn't get up. I made a high lung shot that just nicked the spine. I happened to use a 350 rem mag with a 225gr sierra, but I have little doubt I would have had the same results with a 45-70 hardcast, or a .308 with an expanding bullet, or a 416 rem mag.

If she'd gotten back up or didn't drop at the shot I would have kept shooting until she was down.

Cast bullets can be great, and there can be times when they aren't the best choice. Same with expanding bullets.