Big Country i have a 22-250 and a 7mm remmag with over 500 rounds in each and have not cleaned either of them.I used to clean every 500 rounds but did not find a great deal of copper fouling @ the 500 round mark.I run a nylon bristle brush down the barrel twice and a few dry cotton patches.They still shoot sub 1" to this day.I am not recommending this to anyone,just sharing my experience.If i burn up a barrel i will let it be known.But i doubt that might happen.