NavyLCDR
member
I'm careful to follow the rules and I don't recall any problems. I'm pretty sure that I told the PO what I was sending. The address makes it pretty obvious. I remember a pleasant transaction at the PO. That's why I asked when the rules changed. I guess I can contact the PO and ask.
The earliest Domestic Mail Manual archive the USPS has on their website is from August, 2003:
http://pe.usps.gov/archive.asp
It's been illegal since at least then, and probably since many decades before:
http://pe.usps.gov/Archive/HTML/DMMArchive0810/C024.htm#Xaq5787
1.2Handguns
Pistols, revolvers, and other firearms capable of being concealed on the person (referred to as handguns) are nonmailable unless mailed between the parties listed in 1.3 and 1.5 after the filing of an affidavit or statement required by 1.4 and 1.6.
1.3Authorized Persons
Subject to 1.4, handguns may be mailed by a licensed manufacturer of firearms, a licensed dealer of firearms, or an authorized agent of the federal government or the government of a state, territory, or district, only when addressed to a person in one of the following categories for use in the person’s official duties:
a. Officers of the Army, Coast Guard, Air Force, Navy, Marine Corps, or Organized Reserve Corps.
b. Officers of the National Guard or militia of a state, territory, or district.
c. Officers of the United States or of a state, territory, or district, whose official duty is to serve warrants of arrest or commitment.
d. USPS employees authorized by the Chief Postal Inspector.
e. Officers and employees of enforcement agencies of the United States.
f. Watchmen engaged in guarding the property of the United States, a state, territory, or district.
g. Purchasing agent or other designated member of agencies employing officers and employees included in 1.3c through 1.3e.