leading in the cylender end can be caused by several things, and i forget what, but probably soft lead, to large of bullet in cylender, too small of cylender for bore, problems here are uncommon.. leading in the breach is from stripping of too soft of lead or too hot of load.. leading down the bore is from too little lube, too soft of lube, or too hard of bullet that is under sized and wont bump up.. a medium hard bullet works beautiffully for most pistols and even rifles for reasonable speeds.. its funny how most comercial casters use the hardest lead they can get.. contact bear tooth bullets( use suearch engine to locate) for some cusome high quality bullets of 16-1 lead with gas check.. if your pistol is in good shape it could handle loads from 1000 fps to 1500 fps.. again if your cylinder is not undersized, or misalined, and there is no barrel pinch in your barrel.. in the old days when the smiths screwed in the barrel they sometimes didnt take enough mettal off the male end of the barrel and screwed it in leaving the breach smaller than the bore at the frame... the only remedy for this is with dead soft holow base bullets or a grease cookie to stop blow by. a grease cookie is placed behind the bullet and its two peaces of manila folder with a glob of lube inbetween.. buy bullet lube from your local gun supplier.. this cookie looks like an oreo and this is why its called a crease cookie.. if your getting minor leading and the gun is shooting well for 25-50 rounds a gas check may keep it clean enough for normal shooting.. also if it comes out with bronze brush and 10 minute cleanning job its fine as long as it shoots accuratly.. you may have a non problem if its shooting well .. dave...