Any United States citizen who is in legal possession of a firearm or ammunition thereof pursuant to the laws of any state, territory, possession or Trust Territory of the United States shall have a period of thirty (30) days after arriving on Guam as a new resident in which to apply for an identification card and during that period may continue to use the firearm and, for that purpose, the gun is legally in his possession until an identification card is issued or denied him. Thereafter, all provisions of this Chapter apply in full to such person and he must purchase, possess or use firearms only in compliance therewith. The Section does not apply to any firearm which may not be legally possessed or used, carried or purchased under this Chapter. With respect to such firearms the provisions of § 60123 shall apply except that under this Section the new resident has thirty (30) days in which to comply. Further, this Section does not apply to persons transiting Guam. Such transiting persons shall not have in their possession any firearm on Guam without first obtaining permission therefor from the Chief of Police.

SOURCE: GC § 8910.