Colt Model 1903 Pocket Hammerless The Colt Model 1903 Pocket Hammerless is . 32 ACP caliber , self - loading , semi - automatic pistol designed by John Browning and built by Colt Patent Firearms Manufacturing Company of Hartford , Connecticut . The Colt Model 1908 Pocket Hammerless is a variant introduced five years later in . 380 ACP caliber . Despite the title ' Hammerless ' , the Model 1903 does have a hammer . It is covered and hidden from view under the rear of the slide . This allowed the weapon to be carried in and withdrawn from a pocket quickly and smoothly without snagging . These pistols were popular civilian firearms for much of their life , and also served as United States General Officer pistols from the 1940s until their replacement by the M15 General Officers pistol in the 1970s . The Office of Strategic Services issued the Model 1903 to its officers during World War II . The Shanghai Municipal Police issued the M1908 to its Chinese officers in the 1920s and 1930s and it was a popular back - up / off - duty model with police officers in the United States . In addition to lawful owners , many gangsters of the pre - World War II era favored the Model 1903 and Model 1908 because they were relatively small and easily concealed . It is said that Al Capone kept one in his coat pocket and Bonnie Parker used one to break Clyde Barrow out of jail after smuggling it into the jail by taping it to her thigh . Bank robber John Dillinger was carrying this model of pistol when he was shot by FBI agents outside the Biograph theater on July 22 , 1934 , and another famous bank robber , Willie Sutton kept one when was captured by police in Brooklyn on February 18 , 1952 . Note : There was also a Colt Model 1903 Pocket Hammer pistol in . 38 ACP , but this design is unrelated . The FN Model 1903 pistol design is related to the Colt Pocket Hammerless , but it is physically larger due to its chambering in 9 × 20 mm SR Browning Long cartridge . History . Approximately 570 , 000 Colt Pocket Hammerless pistols were produced from 1903 to 1945 , in five different types ( see Variants paragraph below ) . Some were issued to US Army and US Air Force general officers from World War II through the 1970s . They were replaced in 1972 with the RIA Colt M15 General Officer ' s Model , a compact version of the M1911A1 . General Officer ' s Models . General Officer models were often engraved with the officer ' s name . Recipients included Generals Eisenhower , Bradley , Marshall , and Patton . Patton ' s Model 1908 was embellished with three ( later four ) stars on the grip panels to denote his rank . They were issued with a fine - grade leather holster , leather pistol belt with gold - metal clasp , rope pistol lanyard with gold - metal fittings , and leather two - pocket ammunition pouch with gold - metal fasteners . They came in russet or black leather ( depending on service and regulations ) and were made by ALPCO ( Atchison Leather Products ) or Hickock . A cleaning rod and two spare magazines were also included . Design . As noted above , this pistol was still actually fired by action of a hammer striking and driving a firing pin into a center - fire cartridge ' s primer . The hammer was covered by the rear of the slide . The " hammerless " designation was merely an advertising designation pointing out the pistol ' s particular suitability for concealed carry . Special features include a serrated slide to prevent slippage during manual cycling of the slide , and two safety mechanisms ( a grip safety and a manual safety ) . The grip safety is a spring loaded piece making up the back strap of the pistol . The grip safety , though not solely restricted to them , was a typical feature of Colt automatic pistols . A magazine safety was added on later models ; this feature prevents the pistol from being fired with a round in the chamber and the magazine removed . In 1908 , a . 380 ACP version of this gun was introduced . Called the Model 1908 , it was nearly identical to the Model 1903 except for the bore diameter and the magazine , which held seven rounds ( one less than the Model 1903 ) . Grip panels were black checked hard rubber , checked walnut , or special order materials ( ivory , mother of pearl , inset medallion ) . Sights were fixed , although the rear sight was drift - adjustable for windage . Metal finish was blued or nickel , and some special - order finishes such as engraved , silver or gold plated . Variants . There was also an M1903 version with a military Parkerized finish , which is otherwise the same as the Model IV , SN 554 , 447 through 572 , 214 .