a bronze brush if stroked 20 times or 200 is going to wear a steel barrel?
I don't like brushing that much but I don't see it wearing a barrel personally.
I've done over 1000 strokes with a brush, patch and diamond lap paste and still had copper in a bad barrel..... I"ve done it with JB too.
I just don't see how a brush can wear a barrel.
Should have clarified I was also thinking about damage to the crown, not a brass brush damaging the interior of a barrel.