I found a old colt gun revolver with the serial number 0452 cant find it any where

most public libraries have information books about antique firearms and dates serial numbers etc. Otherwise you are going to have to take it to an appraiser that is an expert in guns.

It is a 32-20 police positive .if you decide to fire it make sure you use the revolver rounds and not the rifle

Call colt. 1-800-962-COLT (2658)

The Colt "DA" (Dept. of the Army) was manufactured Between 1892 and 1942 and are considered to be Pre War (WWII) the SN Look-up on Colt's site does not give a specific year (http://www.colt.com/CustomerServices/SerialNumberLookup.aspx) but they do have an archive service that (for a fee) will research the gun for you and give you details on it origin.

Your gun is a Colt "Lightning" Chambered for Colt .38 long. It was manufactured between 1877 and 1909. Colt web site has a pay-service to research it in more detail..
http://www.colt.com/CustomerServices/SerialNumberLookup.aspx

There were no record keeping requirements until 1968. That hardware company had multiple salesmen that called on hundreds of stores that sold guns. There is no way to track it that I know of.

Serial number comes out to be a colt 1849 pocket revolver made in 1871 values range from around 300 to several thousand dollars depending on condition matching numbers and functionality
The Model 1849 Pocket Revolver, a replacement for the Baby Dragoon, was the most widely produced of any Colt percussion pistol. Nearly 340,000 were manufactured during a 23-year production run that ended in 1873. Although most production took place in Colt's Hartford factory, approximately 11,000 were made in London. These pistols were available with octagonal barrels ranging between 3 and 6 inches in length. The one-piece walnut grips, and casehardened frame, hammer, and loading lever previously featured on Colt's Walker and Dragoon revolvers was carried over to the Model 1849 Pocket, however, the square-back trigger guard was replaced with a round guard, and the engraved cylinder featured a stagecoach holdup scene rather than the Texas Ranger - Indian fight that had been standard on earlier Colts. Approximately 4,000 so-called "Wells Fargo" variants, with 3-inch barrels and without loading levers, were also manufactured

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