Everyone has an opinion on Moose Shot Placement See this below. If a Moose was at waters edge and there was concern that the Moose after the shot might head for water then I might try to break both front shoulders to anchor him. But if not a broadside shot to both lungs just behind the front leg is a sure bet says all the veteran Moose hunters because it is the largest target area and a sure kill.
He may take a minute or two to fall but fall he will. If he stands long enough for a second shot, I would take it.