Bear with me, I am a newbie shotgunner. Within the last week, I purchased a Benelli M3. It has been kept in a gun safe with desicants. I took it out this evening and noticed that the magazine tube was a solid dark brown in color. I immediately thought "rust?". I rubbed the tube with WD40, and could not get any residue off. The tube appears to never have been coated black in color like the rest of the weapon.

Is this normal? I would hate to drive the 70 miles to the dealer to find out I was worried over nothing.

Thanks,
Craig