I don't shoot triple seven and I understand that the crud rings clean up when the barrels are cleaned,,, that little area at the bottom of the barrel where the crud ring develops even if it's cleaned correctly and consistently do you feel like it changes the metal of that barrel in that area? Reason I ask is four different rifles that I've purchased had severe pitting in that quote," crud ring area",, rest of the bore is perfect outside of the guns where immaculate,, the guns look like they had been well maintained I guess what I'm asking is does that crud ring issue end up having a permanent effect on most barrels? And if it does ,,does every time I shoot the gun with just a little bit of a crude ring ,am I adding to that potential change in the metal structure in that area seems like I would be,, I guess if it was just kind of a beater hunting rifle it really wouldn't matter but if it was a rifle barrel I highly valued I would be swapping in between shots probably fanatically.. might be a topic for another post or another thread and I apologize for getting off topic it's just questions I think about.