Rear end noise

I'm stumped on this. Every time I turn right, I get a noise from the right back wheel which sound like the drum rubbing on the backing plate. It's a hollow sound. I've pulled the drum and there is no rubbing marks. I've lifted the rear and rotated the wheels and no noise. I've even swapped the drums. Could it be the bearing? The funny thing is it sounds like a rubbing noise. I get no noise turning left or going straight.