It is very hard to beat USPS priority mail in my opinion. But I have never had a problem so I can't address your query about making a claim against them.

I made a similar box - I used decking cedar (a little lighter than pine). I glued the bottom and side joints, in addition to screws. That box was for a Joseph Lang double rifle and I sent it Registered mail in that instance. It was VERY slow, but VERY secure. I followed on tracking as it was signed in and out of every stop along the way. If you elect to go this way, shoot me a PM.

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BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]