As Azdave noted the J.C. Higgins Model 50 was built on an FN Supreme action. There was also a Model 51, same barreled action but in a nicer stock; a little better wood, checkered and with a cheek piece. These were sold by Sears in the early mid to late '50s. There were only two calibers available, 270 and 30-06; High Standard supplied the chrome lined barrels. When FN's prices went up, Sears switched to Sako actions and changed the Model numbers.
Years ago I had a Model 50 and stupidly sold or traded it for something, then a few years ago I picked up a Model 51, both 30-06. Excellent guns, very accurate, just need to add a nicer trigger like a Timney.
Because of the Sears association, prices on the Model 50 and 51 are often much lower than the actual quality of the guns. If you see one sitting in a shop at an decent price, don't hesitate to buy it, you won't regret it.
Best regards,