a lady at work is trying to find info on her late husbands pistol, it is marked, "Colt DA 45 model 1909 NO 42xxx  she said it is a revolver. i've never heard of this, and do not have pics at this time.

This sounds like a Colt New Service DA Revolver, made in .38 special, .357 mag (intro. 1936), .38-40, .44-40, .44 Russian, .44 special, .45 Auto, .45 long Colt, .45 Eley, .455 Eley & .476 Eley.

Six-shot cylinder, bbl lengths 4-, 5- & 6-inch in .38 & .357 calibers, 4.5-, 5.5- & 7.5-inch in other calibers; 9.75-inches overall length (w/ 4.5-inch bbl.) Weight: 39oz. (45 cal. w/ 4.5-inch bbl.). Fixed sights, Blued or nickel finish. Checkered walnut grips. Made from 1898-1942.

Note: more than 500,000 of these in 45 Auto caliber (designated Model "1917" Revolver) were purchased by the US Government during WW1. These were later sold as surplus to NRA members through the DCM.

Commercial model......... NiB $1619   Ex $1295   Gd $881
Magnum........................ NiB $1031   Ex $825     Gd $561
1917 Army.................... Nib $994      Ex $795    Gd $541


(from 26th Edition Gun Trader's Guide)

Mike

It's a military issue Colt New Service.  I have one in the collection.  It was purchased as a "hedge" against the M1911 not working out.  As the Army looked for an automatic, there was some doubt that one could be found that would actually work the way they wanted.  In 1909 the Army contracted Colt to manufacture their New Service revolver in .45 Colt (not .45ACP like the M1917 was) so that it would have useable pistols already fielded if the M1911 project failed to produce good results.

The Navy and Marine Corps also had a slightly different verison.

Because early experience with the gun showed that the .45 Colt round's small rim could jump the extractor, the M1909 .45 Frankford Arsenal cartridge was developed.  It was a .45 Colt with a bigger rim.

When the M1911 was adopted, the M1909 was replaced by the auto.  In 1917, the Army bought virtually the same revolver, only chambered in .45ACP, as the Colt M1917.  They also bought S&W M1917's, which are different guns, but still revolvers in .45ACP.