My al3 seems pretty smooth on the inside. But, comparing it to a 4c, the 4c is plastic (very smooth), so the al3 may seem a little rough. The baffle on mine is pretty smooth, but the walls have a little roughness (mine's an older one though). It's probably not going to be a used piece (where did you buy it?). For some mouthpiece makers, roughness is an intentional part of the hand-finishing process.