Sharp Shooter
Tyring to stay with in your guidelines for comment... I use BB because I know it reduces fouling, both in my ML's and my shotguns (trap guns). I think the metod of application makes all the difference in the world, of cousr I think I apply it correctly....
BB will cause
leaching if the bore is not perfectly clean... It will leach the old burnt or non-burnt powder from behind the riflings and out of the pores. This might be the "tobacco" stain that cayugad is talking about. I have had it happen in the past also but never really got to concerned - I have actually been hoping to get one again - I want to run one up to the University to have it analized.
I have some old sidehammers that have not been used for years in the back room they have been treated with BB but when I check them I am still getting clean patches....
One last thing I do not depend on BB to prevent rust or seal the barrel - it is just part of the treatment...
If you would like to read the whole process let me know I will send you my procedure....