Undersize bronze brush wrapped with maroon 3M scrubbing pad. Just a thin strip wrapped around brush. Should fit very tight in bore. You can soak it with some type of lube to make it easier. Sometimes a little lube is the humane thing to do. This method is borrowed from Nathan Foster of New Zealand. Look up his complete "how to" on line. I think it's "Ballisticstudies.com" The method has worked wonders for me in the past. Even on my .303 Brit...…..