I finished the barrel assignment! I used Blender instead of Zbrush. I watched Marc's Zbrush tutorial, but it didn't really help with making the barrel in Blender. I had several false starts, and spent a stupid amount of time on this.
I followed several YouTube tutorials to complete the assignment. Grant Abbitt's tutorials for the barrels and texture painting them. Ryan King Art's tutorials for the texture for the metal rings, the wall and the ground.