Recently I bought some cast bullets (148gr DEWC) in .357, and loaded them to shoot in a smith & wesson 686 as .38 spl. After shooting 100 rounds, at approx.960FPS I noticed quite a bit of leading. Can this be reduced by reducing the charge/velocity or is my 686 a picky eater? Also does anyone have any tips for removing leading?

Dvrdwn,
A dedicated pistol shooter can help you a lot more then I can. But these are the basics. Undersized hard bullets will lead the bore,as well as softer bullets driven too fast. Inadequate lube will cause leading,also.
Commercial bullets are usually hard,they may be undersized. I would slug the bore and make sure that it is at least .001 smaller then the bullet diameter.
The best way to remove some lead from the bore is with the Hoppe's lead remover system. If it's really bad,get the Outer's Foul Out System. I don't use mine a lot;but when I do,it'sa godsend.
Frank

Recently I bought some cast bullets (148gr DEWC) in .357, and loaded them to shoot in a smith & wesson 686 as .38 spl. After shooting 100 rounds, at approx.960FPS I noticed quite a bit of leading. Can this be reduced by reducing the charge/velocity or is my 686 a picky eater? Also does anyone have any tips for removing leading?

Before I load a bullet I have not cast I do a Bhn test on it as well as check diameter. If it not .001 to .002 over my bore size I dont mess with them. I try to match my velocity to the Bhn and I always use a good lube. I have found one can remove leading with brass "Kurly Kate brand" or copper "Chore Girl brand" by taking and wrapping it around a loose fitting bore brush to provide a tight fit. 15 to 20 strokes with out solvent will usually remove it all. If the bore is not to heavily leaded, a few HOT loads from a jacketed will do the job as well.

God Bless: Leon