i just went through the same thing.
I did my research, and here are a few sites to help you
www.thegunzone.com/ship-guns.htmlwww.usps.com/cpim/ftp/pubs/pub52.htmcopy the section from the USPS manual concerning firearms,( section 43) hilight the specific areas, hand the clerk a letter certifying that you are in compliance with with the Gun Control Act of 1968 (Public Law 90-618) and 18 U.S.C. 921, is not a short barreled rifle, is not a short barreled shotgun, is unloaded, and you should be good to go.
basicaly according to the USPS, this is the guideline
Unloaded Rifle or Shotgun
Short-barrelled rifles or shotguns that can be concealed on a person are nonmailable.
Mailer must comply with Gun Control Act of 1968 and with the state and local laws. USPS may require mailer to open parcel or give written certification that weapon is unloaded and not concealable. Registered mail service is recommended.
it says nothing about removing the firing pin, or dissassembling the rifle.
they tried that crap with me, and i just said, ":get the manual and show me"
and i also pointed out this regulation
434 Legal Opinions on Mailing Firearms
Postmasters are not authorized to give opinions on the legality of any shipment of rifles or shotguns. Mailers should be referred to the nearest regional ATF office for further advice. See 435 and Exhibit 435.
I told them that the manual does not say it has to have the firing pin removed, and they are not in the position to make opinions on the legality of me shipping my rifle with the firing pin in.
the supervisor shrugged, said I was right, and took my rifle.