WHere can I get information on an old Colt DA 45? On the barrel it has patent dates of 1884, 1900, and 1905. Other than that it is just stamped Colt 45. Serial # of 18020xx. I have an Officers Model Target in .22 that was my grandfathers. This gun looks very similar but with a larger frame and fixed sights. thanks for any help.

Jeff

I share 475 Guy's view--likely a 1917 or New Service.

From "Colt Firearms, 1836-1954", pp. 245, James Serven--reference the barrel markings, produced verbatim:

1. COLT'S PATENT FIREARMS MANUFACTURING CO.
HARTFORD CT. USA. PAT AUG 5, 1884, JUNE 5, 1900

(later....)

2. COLT'S PT. F.A. MFG. CO. HARTFORD CT. U.S.A.
PAT'D AUG. 5, 1884, JUNE 5, 1900, JULY 4, 1905
(Oct. 5, 1926 patent date added later)

Side of barrel marked with various caliber designations, and Army revolvers such as the 1909 and 1917 models marked under barrel "United States Property".

End quote.

Hint on caliber--the 45 ACP revolvers have a relatively large gap between the cylinder's rear surface and recoil shield to accomodate the 45 ACP rimless cartridge clearance + half-moon clip. It will look noticeably wide. The 45 Colt and 455 Eley variants have a narrower and more conventional gap between these surfaces.

Hint #2--open the cylinder and see where the chamber step is located inside the charge hole. If the chamber step is about 3/4 the way down the charge hole, it's likely a 45 Colt. If the chamber step is a little more than halfway down the charge hole, it's either a 45 ACP or 455 Eley. Check the clearance as above--if it's wide, the revolver is likely a 45 ACP. If the clearance is narrow/normal, that pushes thoughts closer to 455 Eley.

CAUTION--MANY of the 1917's have been modified from their original 45 ACP caliber to 45 Colt or 455 Eley, with varying levels of competence. In addition to the 45 ACP/Auto Rim, 45 Colt, and 450/455/476 Eley--the N/S came in other smaller calibers as well.

I suggest an examination by a knowledgeable source prior to firing the piece. There is a VERY RARE Marine Corps variant that has substantial collector value--this variant will show a rounded and narrower butt profile than other N/S variants--per Serven.

Don't overlook the possibility that it may be a model 1909 in 45 Colt. Easily confused with a New Service.