I guess I am not sure exactly what you are asking for sure?

Not to be shot long term... what I am suggesting there is that BH does cause a 'crud ring' type of fouling but it is in the breech plug instead of the bore. At the time of BH's release I do not think this was known for sure. Current breech plugs do not have the ability to shoot long term (many shots) without doing some maintenance to the BP. Gun companies certainly did not know it for sure or they could done more preparation for a BP that would offer more long term shooting capabilities.

Stringing... If you are referring to the target I posted and the ragged group... the only thing that I would comment on is the target was not shot for accuracy, it was shot for velocities one shot after another. The purpose was to check to see if different primers would produce a significant change in velocity, which I do not think it did. At that time i was in a discussion with another forum member that felt the hotter primers would provide a significant velocity increase.

Even the labled shots are approximately locations as the target became chewed up.

Maybe help me understand what you are asking?