Dreaming of a barrel means your hopes and goals are gathered into one centralized location. The barrel contains important information that may assist you in overcoming difficulties and obstacles. Reach your hand into the barrel to see what you pull out for the implied significance of that object in your waking hours.
A barrel in a dream can also signify confinement, being trapped, or having something you need restrained.
If you dream of being in a barrel and can’t get out, it may symbolize that you feel trapped by your circumstances. You may also be feeling confined and unable to do what you want. The same principles apply if the barrel is large enough for you to walk around inside of it.