The sears model 6c-22 was made Winchester/ same as Winchester model#490
That's the Winchester Model 490. A very high quality .22 semi-auto with the weight and feel of a Model 100. Built during 1976-1980. Pricey and hard to find.
Lets start with the Winchester model 490,chambered in 22lr was only made from 1974-1977,while some claim that it was made from 1975-1980.The value of these semi-auto rifles run from 130-185 dollars for a rifle in fair to very good condition.
Depending on condition, up to 450 USD
Try Numrich Arms, also known as Gun Parts Corp (or GPC).They have a huge supply of vintage parts, used and new, and a web site.I've had good luck with them.
Your rifle may be a Winchester Model 490. If so, it should have a button type safety on the side of the trigger guard to the front of the guard. This pushes through from right to left to release the safety. Please contact Winchester through their website for an owner's manual for your rifle.
This gun was made only in Ontario, Canada.
The H&R topper model 490 JR was made from 1961-1983.I hope that you find this informative.
Depending on the model version, horsepower can be from 490 to 550.
490 = 490
Needs to be checked by a gunsmith
490