Auto-Releasing Method and Arrangement of Detachable Magazine for Firearm

A magazine for a firearm having a magazine receiving cavity and comprising a magazine catch mechanism for locking said magazine inserted in the magazine receiving cavity in position, wherein said magazine comprises:

• a magazine casing having a cartridge chamber therein adapted for receiving one or more cartridges and a cartridge opening communicating with said cartridge chamber to allow the cartridges feeding in and out therethrough;
• a cartridge follower housed in said cartridge chamber;
• a resilient element housed in said cartridge chamber and extended between a base of said magazine casing and said cartridge follower for providing a resilient force against said cartridge follower towards said cartridge opening, thereby the cartridges fed in said cartridge chamber are guided one after one between said cartridge follower and said cartridge opening that maintains an uppermost cartridge of said cartridges housed in said magazine at a position of said cartridge opening;
• and
• an auto-releasing arrangement comprising an actuator mounted in said cartridge chamber of said magazine casing in such a manner that said actuator is driven to move up and down along with a movement of said cartridge follower, wherein when said cartridge follower is moved by said resilient element to an uppermost position and adjacent to said cartridge opening while the last cartridge of the cartridges housed in said cartridge chamber is chambered and loaded in the firearm and leaving said magazine having no cartridge therein, said actuator actuates the magazine catch of the firearm to unlock and release said magazine for removal from the firearm, wherein said actuator is an elongated resilient element having an upper end affixed to a lower portion of said cartridge follower and a lower end extended downwardly, wherein said actuator further comprises a protrusion member integrally and outwardly protruded at said lower end thereof.