Here is some info I found. Sounds like you might have a neat little pistol. Sorry about your Grandpa though.
The Colt Model 1903 Pocket Hammerless is .32 ACP self-loading semi-automatic pistol introduced by Colt Patent Firearms Manufacturing Company of Hartford, Connecticut and developed by John Browning.
Five years later the Colt Model 1908 Pocket Hammerless in .380 ACP was introduced.
They were popular civilian firearms for much of their life and served as United States General Officer pistols from the 1940s to the 1970s.
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 x 20mm SR Browning Long.
Approximately 570,000 of these guns were produced from 1903 to 1945 in five different types. Barrel length is 4 inches (102 mm) for Type 1, and 3 3/4 inches (95 mm) for Types 2 through 5. Overall length is 7 or 6 3/4 inches (178 or 171 mm). Weight is 24 ounces (680 g). Magazine capacity is eight cartridges. The most common finishes are blued or nickel, but some special-order finishes were produced, including engraved versions and silver and gold plated models. The Model 1903 usually sports either black checkered hard rubber grips or checkered walnut grips, but other grip materials were used on special orders, including mother-of-pearl and ivory. Sights are fixed, although the rear sight is drift-adjustable for windage.
The Colt M1903 and M1908 Colt Pocket Hammerless pistols were issued to US Army and Air Force general officers from World War II through the 1970s, when stocks ran out. These included Generals Eisenhower, Bradley, Marshall, and Patton
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). A magazine safety was added on later models. Despite the title 'Hammerless', the Model 1903 does have a hammer, but it is hidden from view by the gun's slide. In 1908, a harder-hitting .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).
Specifications
Calibers:
M1903- .32 ACP
M1908- .380 ACP
Weight (unloaded): 930 g
Length: 205 mm
Barrel length: 127 mm
Capacity:
8 rounds (.32 ACP)
7 Rounds (.380 ACP)
Variants
Police marked variations
Military marked variations
Rock Island Arsenal - originally the site from which most Martial Colt Model 1903 & 1908 Pocket Hammerless Pistols were issued to U.S. General Officers, historical information on these models is still maintained here. A letter to RIA requesting information concerning the issue of one of these guns will result in a response which may or may not confirm that a particular pistol was issued from RIA. There is no cost associated with this information. Letters should be addressed to:
Richard C. Neubauer
General Officer Program
Department of the Army
AMSTA-LC-CSL
Tank-Automotive And Armaments Command
1 Rock Island Arsenal
Rock Island, IL 61299-7630
E-mail: amsta-lc-csi@ria.army.mil
Colt's Manufacturing Company, Inc. in Hartford, Connecticut has most of the historical production and shipping information for Colt firearms. The 2005 Colt Historical Services Price List is available online in a PDF format. If you would like to receive a factory letter on a specific pistol, you can contact Colt's directly for more information at the address/phone number listed below:
Kathy Hoyt
Colt Historian
P.O. Box 1868
Hartford, CT 06144-1868
Phone: 800-962-2658
_________________________
Just because I look big, dumb, and ugly, doesn't mean I am. It means I can stomp you for calling me it!