Ruger's web site has sn data.
Go to The Ruger website, check under Customer Service, Historical Data, Pistols, your model, and the serial number ranges for each year are posted. You did not tell us which model.
by serial number
In order to tell how old your Colt 25 semi auto pistol is, you will need to offer the serial number. This number gives you an idea of when the pistol was manufactured.
No such model in the Ruger line.
Ruger's website has serial number data on its products.
100-400 USD
Ruger website, customer service, historical data- and you need the MODEL of the pistol. Your serial number indicates that your Ruger pistol was made in the year 1976.The ending serial number for that year was 13-48646.
If Ruger's website is up, they have extensive sn data on it.
Call Ruger and they will tell you. Go the Ruger website and use the serial number date function.
Go to Ruger's website. They have a sn look up section.
Ruger has a sn search function on their web site.