I wouldn't play word games with Fedex or UPS insurance unless one wants them to play word games with you if things go south. Insurance carriers make money taking premiums not paying claims and will do what they can to avoid paying a claim, especially what they'd consider to be a material misrepresentation in their eyes. If Fedex or UPS won't agree to send a gun barrel which is not a firearm, then what would you expect them to do if the "steel tubes" are lost or stolen? Send USPS registered. Typically, your firearms insurance would cover a lost item in the mail or shipment. Gil