"would guess they are low to mid grade?"
Their minimum order is 100 barrels. They'll make them as good as you're willing to pay for. Blanks, finished, coated, chromed bore, etc.
"Founded in 1954, the Company began specializing in large volume gun barrel production in the early 60’s. Today the Company produces a variety of barrels ranging from .17 caliber to .50 caliber and is poised to provide gun barrels in various stages of completion (from blanks to finished barrels) to most of the world’s major gun manufacturers supporting military, law enforcement and sport enthusiast applications. "
Fwiw, Cooper rifles used Wilson barrels. Wilson bought Cooper in 2009.