I use only bronze brushes in my guns. It may only last 1/4 of the time a SS brush will last, but I know I'm not gonna damage my barrel, and for the extra $2-4, that's nothin'. I buy 'em in bulk from Orion, or Brownell's. I get them to last quite a bit longer by immediately dipping them in 99% alcohol after I've finished the last stroke through the bore. Alcohol dries very quickly, and it cleans off the Hoppes well, so the bristles don't deteriorate as quickly.