I have some similar marks on my barrel and don't worry about them; the gun functions flawlessly. The barrel is relatively thick on the SR9 and the gun works properly every time. These are little scratches, a matter of internal cosmetics much more than function.
All machines wear a little differently no matter how carefully they're manufactured, and this goes for large pieces of equipment and small ones: that's why technicians who are qualified to service large pieces of equipment are valuable.
I'm in the printing business and you can take two brand new, identical iterations of a machine from a major supplier like Hewlett-Packard and yup, they each will wear slightly differently, different parts will break when you push them. A bushing will wear out a little faster on one than the other, a spring will go out of tolerance, a belt will start to degrade on the other before the first one does. All mechanical devices we make are manufactured within overlapping windows of tolerance that effect each other in sometimes unpredictable ways.
It's not a perfect world. We keep trying and trying but it just isn't. :)
Aside from the philosophical musings, if the gun isn't unsafe and it is working well, you don't really have a problem. I don't worry about the marks similar to yours on my barrel. You just have a normal manufacturing variation.
In a purely Platonic world they wouldn't be there, but then again in a purely Platonic world you might not ever need to buy a defensive $400 9mm pistol. :wink:
Also, when I feel the barrel on my SR9 instead of just looking at it, there are serrations in the barrel that come from the manufacturing process: it is a machined piece. There are going to be some tool marks and odd wear patterns on anything that has a couple of thousand microscopic grooves in it.
Don't worry about it.
