This standard is a revision of and supersedes NIJ Standard-0112.00 dated April 1986. The headspace requirements for 9mm pistols have been changed to conform to industry standards, and a test method has been added to measure headspace of pistols in which the breech block is not in contact with the rear surface of the barrel when in the firing position. The standard addresses 9mm and 45 caliber single and double action pistols only. The standard is for use in assessing the acceptability of new or reissue autoloading pistols. Requirements in the standard pertain to acceptance criteria, user information, visual inspection, dimensions, function, firing, drop safety, and drop function. Tests for determining these requirements are described. Appended supplementary information.