Mossberg 500 c barrel issue, and question.?

Quick question, just picked up a slightly used mossy 500 c with a 28 in barrel and I'm planning on bringing it to the range next weekend, but this morning I noticed something about the barrel. Since I bought the gun used I wanted to give it a quick cleaning before I put it away, so I removed the barrel cleaned her up and put it back together, super routine (I learned how to shoot and break down this same model as well as the remington 870 when I was ten years old and have been doing it since- so I'm sure I didnt make an error putting the barrel back on). But, I was looking over the gun once I had it back together and I noticed the grooves at the top of receiver did not exactly line up with the grooves at the top of the barrel -Its as if the barrel is turned ever so slightly to the left when locked into the receiver if I'm looking down from butt to muzzle. Honestly, if I hadn't noticed this I would have gone shooting and I'm sure everything would have been fine but now its got me thinking. I took the barrel off a few more times just to make sure it wasnt my error, and it truly wasnt, that's the way to gun goes together at its smoothest. I even took the thing outside and loaded 3 rounds into it, and they slide into the chamber nice and smooth, so no issues there. Does anyone have experience with this or any suggestions? I know its a bit nit-picky but I'd really like to not loose any fingers when I go blastin...