 The DAO or 'Bobbed Hammer' Detective Special was otherwise the same as the standard Fourth Series Detective Special.Interest has arisen over the use of higher-pressure (+P) .38 Special ammunition in the Detective Special.In their more recent owners manuals, Colt authorized limited use of +P ammunition in steel-framed revolvers (including earlier versions), citing 2000 to 3000 rounds before recommending the gun be returned to the factory for inspection.