International or Domestic shipped barrels in 3" and 4" heavy walled PVC pipe are secure and arrive safe at their destination.
This PVC pipe is available at Home Depot and other hardware stores as are the matching PVC end caps.
One non-opening PVC end cap is glued onto the tube with PVC glue and also duct taped for security. The other opening end is duct taped in place and noted as the opening end with a felt tip pen.
The barrels are wrapped tightly in an old cotton bath towel and taped tight with 3" masking tape which is easy to remove from the cotton, unlike other tapes which are not easy to remove.
If wrapped properly, there is absolutely zero movement inside the PVC tube and the contents are centered in the towel and secure. As an example, this particular tube has been back and forth Internationally a couple of times, through International customs about four times and is still on the go.....