Noise coming from rear brake drum (right side)

[.eL]

I'm not sure how this started but I did notice it immediately after rotating my wheels.
The problem is this cyclic noise coming from my rear right brake drum. It's an obvious metal contacting metal sound in a cyclic occurrence. It happens all the time, while braking or accelerating.

I took off my drum to do a visual inspection and didnt notice anything and when I put everything back together, the sound was gone.

A day later though, I'm hearing the sound again and it's either just as bad or worse than before. The pads looked fine to me and I didnt notice anything abnormal so I'm completely baffled by this.

Any ideas?