Carbon fiber is the way to go - Tipton Deluxe 1-Piece Carbon Fiber Cleaning Rod 17 - 20

Tipton makes very good carbon fiber cleaning rods, you won't be disappointed with them. They are ridged yet flexible and wont hurt your muzzle crown. There is a lot of talk on the internet about aluminum & stainless steel cleaning rods that can or may damage the crown of gun barrels.. I am not sure what to believe but carbon cleaning rods have been out long enough that they have proven to work well for their purpose and hold up very well. The price of carbon cleaning rods are more expensive than rods of different materials but they are not so costly that it puts too much damage in your wallet. I would rather lean towards the cautious side and go with a carbon cleaning rod than find out I made a mistake some where down the road and possibly caused damage to an expensive gun.