Bad scene. While you may have paid extra to have the seller (shipper) insure the package, the contract to deliver the goods is between the shipper and the carrier. Your agreement is with the shipper to send you an undamaged gun. Even if the carrier pays the claim to the seller, the seller has to settle with you - either he fixes the gun to your satisfaction and then ships it to you, or he pays you off and keeps the gun (assuming the insurance carrier does not take possession of it as part of their settlement with him!).
Your transaction with the seller as of now is incomplete. It's still his gun.
