Bravo 4, I would not reverse direction in bore with a bronze brush, as I know this is a no-no, my thought was since I had some 8mm bronze brushes laying around, I would use them. A local bench shooter I spoke to recently told me that a 30 caliber brush does not make enough "contact" inside bore of 30 cal. rifle, so he uses next "size up".
Is there any benefit to using nylon brushes over bronze, if all you are doing is transferring solvent to the bore anyways, and the solvent is doing all the work prior to running clean patches through, and repeating process as necessary ?