Time served or time sentenced has nothing to do with it:
18 U.S. Code § 931 - Prohibition on purchase, ownership, or possession of body armor by violent felons
(a)In General.—Except as provided in subsection (b), it shall be unlawful for a person to purchase, own, or possess body armor, if that person has been convicted of a felony that is—
(1)a crime of violence (as defined in section 16); or
(2)an offense under State law that would constitute a crime of violence under paragraph (1) if it occurred within the special maritime and territorial jurisdiction of the United States.
And:
18 U.S. Code § 3156 - Definitions
(3)the term “felony” means an offense punishable by a maximum term of imprisonment of more than one year;
(4)the term “crime of violence” means—
(A)an offense that has as an element of the offense the use, attempted use, or threatened use of physical force against the person or property of another;
(B)any other offense that is a felony and that, by its nature, involves a substantial risk that physical force against the person or property of another may be used in the course of committing the offense; or
(C)any felony under chapter 77, 109A, 110, or 117
And:
18 U.S. Code § 921 - Definitions
(20)The term “crime punishable by imprisonment for a term exceeding one year” does not include—
(A)any Federal or State offenses pertaining to antitrust violations, unfair trade practices, restraints of trade, or other similar offenses relating to the regulation of business practices, or
(B)any State offense classified by the laws of the State as a misdemeanor and punishable by a term of imprisonment of two years or less.
What constitutes a conviction of such a crime shall be determined in accordance with the law of the jurisdiction in which the proceedings were held. Any conviction which has been expunged, or set aside or for which a person has been pardoned or has had civil rights restored shall not be considered a conviction for purposes of this chapter, unless such pardon, expungement, or restoration of civil rights expressly provides that the person may not ship, transport, possess, or receive firearms.
The issue is whether the crime could be punishable by a sentence greater than one year (federal) or two (state). Not whether that was the sentence actually given.