Laura Ramsey has been cast as the lead in the pilot of The Sixth Gun, according to Deadline.  The pilot, for NBC, is based on the Oni Press series by Cullen Bunn and Brian Hurtt (see "NBC Orders Pilot for 'The Sixth Gun'").  Ramsey appeared in Lords of Dogtown, The Ruins, and Mad Men. 

Three other cast members have also been signed, W. Earl Brown, Graham McTavish, and Aldis Hodge, according to Deadline.