The Hound of the Baskervilles (1939)
The Hound of the Baskervilles is an American 1939 screen adaptation of the famous detective novel by Arthur Conan Doyle, directed by Sidney Lanfield and starring Basil Rathbone as Sherlock Holmes and Nigel Bruce as Dr. Watson. This movie marks the first of fourteen Sherlock Holmes films starring Rathbone and Bruce as Holmes and Watson.
The following weapons were used in the film The Hound of the Baskervilles:
Colt 1878 Double Action
Dr. Watson (Nigel Bruce) uses a Colt 1878 Double Action revolver in the scene in Baskerville Hall. During the following hunt for the escaped convict same looking revolver (possibly same prop reused) is seen in hands of Sir Henry Baskerville (Richard Greene) (and Watson's gun switches to a Colt 1878 Philippine model revolver). Sherlock Holmes (Basil Rathbone) uses a Colt 1878 when he and Watson fire at the hound.
Colt 1878-1902 Philippine Model
During the hunt for escaped convict, Dr. Watson's revolver switches to a Colt 1878-1902 Philippine Model, a U.S. Army issued version of Colt 1878 Double Action (this revolver is also incorrectly referred as "Alaskan Model"), identified by its larger trigger guard. Same revolver is used by Stapleton (Morton Lowry).
Iver Johnson Bulldog
When Stapleton (Morton Lowry) stalks Sir Henry Baskerville in London, he draws a compact revolver that appears to be an Iver Johnson Bulldog revolver in .38 (most likely) or .32 caliber. Note: this revolver is often referred as U.S. Revolver Co. production, but this company was a subsidiary of Iver Johnson.
Colt revolvers are seen on promotional images in hands of Holmes and Watson. Watson's revolver is very likely a Colt Pocket Positive, while Holmes' one looks larger and may be a Colt Police Positive. Both revolvers doesn't appear in the movie.