1977
That is not a model number, but the serial number. Go to the Ruger website, look under customer service, historical data, Slect rifle, shotgun, pistol or revolver, then find your model. There is a serial number/ year list for all Ruger products.
Ruger website, under Customer Service, Historical Data, pick rifle pistol revolver or shotgun, then your model, and date of manufacture by serial number range is shown.
The Ruger website has sn data on it you can look at.
You will have to call Ruger to find out.
Ruger has sn data on their web site.
Ruger's website has sn data you can access
Ruger has sn data on their web site.
Ruger's web site has extensive sn data.
You will have to find the ATF data for that year. Ruger will not tell you.
Ruger has sn information on their web site.
1960 according to the Ruger website.
If the Ruger website is up, it has sn data.