Go to Ruger's web site. They have sn data you can look up.
We can't tell without the serial number- but if you go to the Ruger website, under Customer Service, you can see the year of manufacture for serial numbers. You will need the spefic model of your rifle.
100-440 or so
1/10
100-450
If sales falter, yes.
The Ruger website, under customer service, historical data, rifle, M77, will have the serial number ranges for each year of production.
100-400 or so
100-560 or so
see below
100-650 usd
Contact Ruger customer service through the Ruger website. Soem parts will require the rifle be returned to the factory for fitting.
300-500 USD