That indeed depends of the wanted result with the barrel behavior overall : must it be stopped when touching the floor? Will it go through? Will its position be reset after that?
Providing as much details as possible is the best way for people to help you on your game, the more details we have, the better we can look for a solution for you ~
Tho from what I understand so far, the barrel must hit the floor, in that case Plateform is the best behavior, however if you change your mind, Custom Movement would be perfect for that, as it allows you to move an object horizontally and verticaly, then handle any collisions through "code"