Pro-Shot Products 17/177 Caliber Nylon Rifle Brush - Pro-Shot Premium Heavy Duty Nylon Bristle bore brushes are made with a tightly wound brass core and oversized extra thick fill bristles. The thicker, stiffer grade bristles allow for back and forth action and eliminate heavy fouling fast. FEATURES: Pro-Shot Bore Brush - Precision Engineered Design, Fit, & Function Superior Heavy Duty Stiff Nylon Bristles with Extra Thick Fill Precision #5-40 Threads Made in USA