If you or your customer has one of those guns that drives tacks or knocks down birds every time, the slight extra cost of our Special Line brushes is well worth it to eliminate any chance of the cleaning brush�s shank putting a scratch in that all-important barrel. The Brass shank is one-piece, looped and wound, (not two, twisted together and chopped off). The coupling is no-scratch Brass. The bristles are the best, phosphor, bronze scrubbing wire for long life and thorough cleaning.