Since darn near as many bore brushes get used in the shop as get sold, we've packed these custom-made, top quality brushes in bulk paks to make them more convenient and less expensive. The shank is one-piece, looped and wound (not two, twisted together and chopped off). Bronze Bore Brushes - Best phosphor bronze scrubbing wire, for long life, thorough cleaning. SPECS: Bristles: Available in bronze. Shank: Steel, looped and wound. Rifle: 3.26" (8.3cm) OAL, .17 and.20 caliber 5-40 threads, all others 8-32 thread. Mfg: Brownells