Finally found a load that could gum up the Benelli. Rio steel shot. Has a unique smell to the powder burn as well. Leaves a flat carbon build up in the gun. Dirty as heck. I think with the really fast shells despite what load you shoot, you will find unburned powder. I have ran the gauntlet of shells through my guns. Some of the finer grains of powder used seem to burn out our leave less residual behind. The larger grain powder like Kent and Winchester use always seem to be found afterwards in the gun upon cleaning. Slower shell, might provide a better burn possibly, but not sure. Speed seem to kill better with the steel, so I will keep shooting those. Above 1,650 fps, things seem to start breaking on the guns if you shoot enough of them.
