I have my firearms insured with Collectible Insurance Agency(CIA). All I have to do is ship priority USPS with $201 in insurance so a signature can be obtained and I'm automatically insured for the full value of the firearm. I've had one clain for $1500 over the years and this was paid.
Additionally; I double pack any firearm I'm shipping. If it's a double for example I'll use a hard fitted case inside a sturdy cardboard box.
Jim

The 2nd Amendment IS an unalienable right.