Ok I got thinking about how so many people post on here that they get a really dirty burn and/or flakes of unburnt powder in barrel and action of gun when the pressure is low. I got thinking about this issue when reloading shotgun shells with our favorite 10mm powder, blue dot. The 12 gauge only operates at like 10,000 PSI, ultra low pressure compared to our 10mm loadings, yet the inside of the barrel is very clean after shooting shells with blue dot, appears to burn real clean overall and no flakes of unburnt powder anywhere. It seems to me that you could have a real high pressure loading with really short barrel and get the dirtyness in that case, right? I'm just curious to hear thoughts from you all on this issue.