Shot placement is critical regardless, assuming you are shooting a reasonably powerful cartridge. I believe the .30-30 is enough. They are tough heavy skinned animals, so I would go with a tough heavy bullet. They will go down if properly hit, they won't if they are not. I've not hunted moose, but all the hunting shows I've seen, I don't believe I've seen one go down at the shot. They all wander around a bit.
My bigger concern would be getting within 100 yards of a dangerous animal. I am a huge fan of the .30-30, I have four of them. I harvest the vast majority of my deer and hogs with them. That said, if I'm moose or elk hunting, I will be fishing the 7mag out of the back of the safe. Not so much for power, but for distance.