I figure it best to use their own system to your favor. With that in mind I've found that if I use the longer triangle tubes that you can get off of their website, you can fit the barrels into one, securely packaged in bubble wrap. and the butt end and forearm in the other, packaged in bubble wrap as well. Ship them express or priority and insure each for the total value. As an aside I never use Priority as it is just an overpriced regular mail service and tracking on it is just delivery confirmation. Express is much much more reliable and can be tracked through its progress. Be sure to insure!!! They don't lose packages that could cost them a couple grand...
good luck.
