This is right from the DOJ Firearms web site, Penal Code section 12285:
b)(1) Except as provided in paragraph (2), no assault weapon possessed pursuant to this section may be sold or transferred on or after January 1, 1990, to anyone within this state other than to a licensed gun dealer, as defined in subdivision (c) of Section 12290, or as provided in Section 12288. Any person who (A) obtains title to an assault weapon registered under this section or that was possessed pursuant to subdivision (f) of Section 12280 by bequest or intestate succession, or (B) lawfully possessed a firearm subsequently declared to be an assault weapon pursuant to Section 12276.5, or subsequently defined as an assault weapon pursuant to Section 12276.1, shall, within 90 days, render the weapon permanently inoperable, sell the weapon to a licensed gun dealer, obtain a permit from the Department of Justice in the same manner as specified in Article 3 (commencing with Section 12230) of Chapter 2, or remove the weapon from this state. A person who lawfully possessed a firearm that was subsequently declared to be an assault weapon pursuant to Section 12276.5 may alternatively register the firearm within 90 days of the declaration issued pursuant to subdivision (f) of Section 12276.5.
(2) A person moving into this state, otherwise in lawful possession of an assault weapon, shall do one of the following:
(A) Prior to bringing the assault weapon into this state, that person shall first obtain a permit from the Department of Justice in the same manner as specified in Article 3 (commencing with Section 12230) of Chapter 2.
(B) The person shall cause the assault weapon to be delivered to a licensed gun dealer, as defined in subdivision (c) of Section 12290, in this state in accordance with Chapter 44 (commencing with Section 921) of Title 18 of the United States Code and the regulations issued pursuant thereto. If the person obtains a permit from the Department of Justice in the same manner as specified in Article 3 (commencing with Section 12230) of Chapter 2, the dealer shall redeliver that assault weapon to the person. If the licensed gun dealer, as defined in subdivision (c) of Section 12290, is prohibited from delivering the assault weapon to a person pursuant to this paragraph, the dealer shall possess or dispose of the assault weapon as allowed by this chapter.
(c) A person who has registered an assault weapon under this section may possess it only under any of the following conditions unless a permit allowing additional uses is first obtained under Section 12286:
(1) At that person's residence, place of business, or other property owned by that person, or on property owned by another with the owner's express permission.
(2) While on the premises of a target range of a public or private club or organization organized for the purpose of practicing shooting at targets.
(3) While on a target range that holds a regulatory or business license for the purpose of practicing shooting at that target range.
(4) While on the premises of a shooting club which is licensed pursuant to the Fish and Game Code.
(5) While attending any exhibition, display, or educational project which is about firearms and which is sponsored by, conducted under the auspices of, or approved by a law enforcement agency or a nationally or state recognized entity that fosters proficiency in, or promotes education about, firearms.
(6) While on publicly owned land if the possession and use of a firearm described in Section 12276 or 12276.1 is specifically permitted by the managing agency of the land.
(7) While transporting the assault weapon between any of the places mentioned in this subdivision, or to any licensed gun dealer, as defined in subdivision (c) of Section 12290, for servicing or repair pursuant to subdivision (b) of Section 12290, if the assault weapon is transported as required by Section 12026.1
I believe the military exemption is covered by this section of the code as are new residents moving into California with firearms that are classified as Assault Weapons. It appears that if a person who was stationed here for active duty decided to stay here afterwards, then they would be covered. I would wait and see what the Master Chief comes up with and go with that.