Army Combat Vehicle Industrial Base Study Validation Act of 2013 - Requires the Comptroller General (GAO) to report to the congressional defense committees on the Army's study of the Bradley Fighting Vehicle industrial base submitted to Congress pursuant to the conference report on the National Defense Authorization Act for Fiscal Year 2013. Requires such report to: (1) address each of the combat vehicles included in the study, (2) include an assessment of the reasonableness of the study's methods, and (3) include findings and recommendations on the combat vehicle industrial base.