I have now about 75 rounds through this SW 380 bodyguard and noticed today after the end of a few clips (only 6+1 straight stack) that it had an odd "sputtering" effect in the lower twist pit of the barrel. Please 'excuse the terminology, I think the photo speaks for itself. The other areas around the barrel had a clean and consistent look. Is this what I should expect? I was shooting Winchester 380 ammo. Have been since I been breaking her in "new" from BPS that showed someone else got a few boxes threw it. So perhaps its' more like 150 to 175 rounds. Probably normal right?