In most states, forever. In order to ever be allowed in possession of a firearm again, you usually must get a special pardon from the Governor's office. After 5 years, they may offer a partial pardon (gives back voting and jury duty rights), but there is typically an appeal process for the full pardon which will remove the Felony status altogether. Generally, as long as you're considered a convicted felon, you can't possess a firearm. Not sure if Alaska law differs from this. Sorry.

From the Bureau Of Alcohol, Tobacco, and Firearms, BATF Form 4473 Question 12.C Notice 6, Exception 1: "A person who has been convicted of a felony, or any other crime, for which the judge could have imprisoned the person for more than one year, or who has been convicted of a misdemeanor crime of domestic violence, is NOT prohibited from purchasing, receiving, or possessing a firearm if: (1) under the law where the conviction occurred, the person has been pardoned, the conviction has been expunged or set aside, or the person has had civil rights (the right to vote, sit on a jury, and hold public office) restored AND (2) the person is not prohibited by the law where the conviction occurred from receiving or possessing firearms. Persons subject to this exception should answer "no" to 12 C. or 12i, as applicable. A person who has been convicted of a misdemeanor crime of domestic violence also is NOT covered by the Prohibition unless: (1) the person was represented by a lawyer or gave up the right to a lawyer: and (2) if the person was entitled to a jury, was tried by a jury, or gave up the right to a jury trial. Persons subject to this section should answer "no" to 12i. " But laws change and vary from state to state, so simply check with an attorney where you live.

hahahahahaha... depends on the vendor really