Leading can be reduced by using gaschecks on cast bullets and of course breaking in a new barrel properly reduces lead wash. Corbin reloading sells a hi tech machining cleaner consisting of micron small glass beads in an emulsified liquid.The cleaning process is mechanical vs chemical. The beads are physically compressed betwen the swab and barrel and literally scrape everything that didn't come from the factory. Excessive leading of a barrel is usually the result of to soft a alloy and higher velocities than the slug can handle without stripping in the lands. Aside from accuracy loss, you will slowly build up pressures that replicate stiff loads and reliability loss. The famous Bill Jordan explained this at a gunshow to a priveledged small audience ( me and 2 others) stating even the famed Model 27 could be locked up with some of the excessively stiff .357 loads in it's early days. Makes you wish we could cary dueling swords again, doesn't it <img src="/images/graemlins/crazy.gif" alt="" />