I just picked up a new ar and noticed some discoloration around the pin on the front sight. I have another rifle of the same brand and it doesn't have it which doesn't really mean anything so I thought I'd ask all you guys. Anyone ever see this before? It's present on both sides and they are near perfectly circular. I am sure it has something to do with manufacturing and is normal but thought I'd ask. Also, I tried a qtip with some solvent just to make sure it isn't light surface rust and it isn't. Thanks guys!