EA Gun Club is no longer available and the site has been taken down so you cannot access the M1911 via the Gun Club promotion any longer. However since the M1911 is the veteran weapon in BF3 you can still access it if you have a Battlefield veteran status of 1 or greater to access it. That means that you've played BF3 and at least one other Battlefield game while logged into your Origin account. You can get veteran status very cheaply by buying a used copy of Battlefield Bad Company 1 or Bad Company 2 which should all be very inexpensive in the used section, or you can play one of the free web based Battlefield titles such as Battlefield Heroes http://www.battlefieldheroes.com/en/ or Battlefield Play 4 Free http://battlefield.play4free.com/en/ while logged in with your Origin account. These two titles will give you veteran status as well.
