Found this on the PA firearms owners forum:
here's the info on non-immigrant aliens:
http://www.atf.treas.gov/firearms/faq/faq2.htm#rheres a sample, I suggest people read this:
(R1) May nonimmigrant aliens legally in the United States purchase or possess firearms and ammunition while in the United States?
Nonimmigrant aliens generally are prohibited from possessing or receiving (purchasing) firearms and ammunition in the United States.
There are exceptions to this general prohibition. The exceptions are as follows:
nonimmigrant aliens who possess a valid (unexpired) hunting license or permit lawfully issued by a State in the United States;
nonimmigrant aliens entering the United States to participate in a competitive target shooting event or to display firearms at a sports or hunting trade show sponsored by a national, State, or local firearms trade organization devoted to the collection, competitive use or other sporting use of firearms;
certain diplomats, if the firearms are for official duties;
officials of foreign governments, if the firearms are for official duties, or distinguished foreign visitors so designated by the U.S. State Department;
foreign law enforcement officers of friendly foreign governments entering the United States on official law enforcement business; and
persons who have received a waiver from the prohibition from the U.S. Attorney General.
Significantly, even if a nonimmigrant alien falls within one of these exceptions, the nonimmigrant alien CANNOT purchase a firearm from a Federal firearms licensee (FFL) unless he or she (1) has an alien number or admission number from the Department of Homeland Security (formerly the Immigration and Naturalization Service) AND (2) can provide the FFL with documentation showing that he or she has resided in a State within the United States for 90 consecutive days immediately prior to the firearms transaction.
[18 U.S.C. 922(g)(5)(b) and 922(y), 27 CFR 478.124, ATF Rul. 2004-1]
(R2) Typically, who are "nonimmigrant aliens?"
In large part, nonimmigrant aliens are persons traveling temporarily in the United States for business or pleasure, persons studying in the United States who maintain a foreign residence abroad, and certain foreign workers. Permanent resident aliens are NOT nonimmigrant aliens. Permanent resident aliens often are referred to as people with "green cards."
(R3) How do I obtain a waiver from the Attorney General?
You should contact ATF’s Firearms Programs Division for information on that procedure. However, in order to apply for the waiver you must have resided in the United States continuously for at least 180 days prior to submitting your application.
(R4) I'm a nonimmigrant alien. I have a State concealed weapons permit. Does this exempt me from the prohibition on nonimmigrant aliens possessing or receiving firearms and ammunition?
No. A State concealed weapons license/permit does NOT satisfy the hunting license or permit exception to the prohibition.
(R5) What is an alien number or admission number?
These are 2 different types of numbers. An admission number is the number on an INS Form I-94 or INS Form I-94W, the arrival/departure form Customs and Border Protection (CBP) gives most nonimmigrant aliens when they arrive in the U.S. While most nonimmigrant aliens will automatically receive an admission number when they enter the U.S., Canadians will not. However, if a Canadian asks a CBP official for an admission number when he/she enters the United States, he/she will be given an admission number. Most nonimmigrant aliens will not have an alien number. An alien number is a Department of Homeland Security file number. It is issued in a variety of limited situations, such as to nonimmigrant aliens with employment authorization documents.
(R6) I am a nonimmigrant alien. I purchased a firearm in Maine in early 1998 after providing the Federal firearms dealer with documentation showing I had resided in the State for more than 90 days. I was told that this transaction was legal then. Am I entitled to keep that firearm and any ammunition I have on hand? Is there a "grandfather" clause that would protect me from criminal liability?
Since October 21, 1998, when the Gun Control Act was amended to make nonimmigrant aliens a new category of prohibited persons, nonimmigrant aliens generally have not been able to possess firearms and ammunition in the United States. The law does not contain a "grandfather clause." Therefore, unless you obtain a valid State hunting license or permit (or fall within one of the other exceptions), your possession of the firearm and ammunition is NOT legal.
(R7) I have a "green card" and have lived in Texas for several years. Am I prohibited from purchasing firearms and ammunition from an FFL in Texas?
As long as you are not otherwise prohibited from purchasing or possessing firearms and ammunition (for example, a felon), Federal law does not prohibit you from purchasing or possessing firearms or ammunition. However, you will need to put your alien number or admission number on the Form 4473 and provide the FFL with documentation establishing you have resided in Texas for more than 90 consecutive days preceding the transaction. Moreover, you must make sure there are no State or local restrictions on such a purchase.