Matthew Short, left, of Fort Worth and Phoenix Horton of Denton watch Mudoch Pizgatti, right, of Plano, uses the Ghost Cutter CNC machine to manufacture a lower receiver for an AR-15 gun during a rally by open carry activists at the state Capitol in Austin on Tuesday Jan. 13, 2015.
Matthew Short, left, of Fort Worth and Phoenix Horton of Denton watch Mudoch Pizgatti, right, of Plano, uses the Ghost Cutter CNC machine to manufacture a lower receiver for an AR-15 gun during a rally by open carry activists at the state Capitol in Austin on Tuesday Jan. 13, 2015. Jay Janner AP
Matthew Short, left, of Fort Worth and Phoenix Horton of Denton watch Mudoch Pizgatti, right, of Plano, uses the Ghost Cutter CNC machine to manufacture a lower receiver for an AR-15 gun during a rally by open carry activists at the state Capitol in Austin on Tuesday Jan. 13, 2015. Jay Janner AP