Ok, I have had several revolvers in the past but my new sp101 is ss of course. Now, here is my question, When I clean my revolver, especially the cylinder, I noticed some little rings toward the end of the cylinder. Now, these are not carbon marks from shooting 38 special out of my sp101 357. Looks like they are made into the cylinder. Are these actually what is called a cylinder throats? Just wondering. When I was looking at these in low light, I though it might be carbon rings or qunk from shooting the 38 specials. After getting a flashlight, I notice again these rings seem to be made into the cylinder. I never have been able to really notice these on my other revolvers. Can someone educate me on this.