Guam and the Marianas Islands are covered by this court too, so this should answer some questions for them as well. However, considering he make up of the court, its by far not a sure thing. You have, currently active, 11 Clinton appointees, 2 Carter, and 7 Obama. On the other side of the line, 2 by Reagan and 7 by Dubya. This could be problematic.
According to Public Law 95-486 (95th Congress, Oct 20, 1978) Section 6 "Any court of appeals having more than 15 judges may constitute itself into administrative units complete with such facilities and staff as prescribed by the administrative office of the United States Courts and may perform its en banc function by such number of members of its en banc courts as may be prescribed by rule of the court of appeals.
9th Circuit has 29 active judges. 20 have been appointed by Anti gun type presidents. An en banc for the 9th is normally 11 judges.
Peruta was decided along party lines, with Chief Justice Thomas being the lone dissenter in the case, as he was in Baker v. Kealoha. It looks to me like an activist judge wants to legislate from the bench, and when he didnt get his way, he called in his cavalry.