Armie Hammer's Wife -- I'm Finally Getting Hammered!!!

Elizabeth Chambers is finally ditching something she's held near and dear to her -- her maiden name.

Chambers and Armie Hammer were married back in 2010 ... but she never took his name, choosing instead to go by Elizabeth Crawley Buntin Chambers (no Downton Abbey relation).

The Lone Ranger's wife has filed docs in LA -- asking to legally become Elizabeth Chambers Hammer.

Several benefits ... being a Hammer's a good thing, it's easier to write, plus she now has a pass to rock parachute pants ... they're making a big comeback!