Hi Jim:
I have found that J-B compound is not very abrasive!! Will not harm a barrel.
Flitz will wear a barrel as it is slightly abrasive.
I have not used losso but I think that it is abrasive like the Flitz.
Many years ago, when Hodgon started selling ball powders, people claimed that ity left a fouling behind that was difficult to remove. Hodgon suggested that one used Bon Ami cleanser to clean the ball powder fouling from rifle barrels. I have done this for about 50 years and I have not had any problems. Mix a paste of oil and Bon Ami and use it on a cloth patch.
I have been told that the abrasive in J-B bore paste and the abrasive in Bon Ami are one and the same. Perhaps the abrasive in the J-B has been screened for a more consistent size.
What are you attempting to remove?
Good luck,
Franchi
