There are lots of ways to ship stuff that works for single events. These can be cheap or expensive. Assuming you can separate the barrel from the stock, the cheapest method would be to take 2 of he cases new guns are sold in pack the barrel in one and the stock in the other, use plenty of zip ties and packing tape on the cases then over wrap them in cardboard. This can be used repeatedly but it is a PITA.
Traveling cases are a different subject. The equipment we build is shipped in cases that have a long life. They are Rotomolded. They are expensive even in large quantities. They will accept abuse like no case I have seen.
The next cases are aluminum (they dent and crack), wood (subject to breaking), and injection molded cases.
I wouldn't travel with anything less than a Pelican injection molded case. Understand, overload that case and drop it from 8-10 feet on a corner and it will crack too. I also would only travel with custom cut foam inside the case. Handles and latches are also subject to breakage given high enough usage.
