I have used .357-.358 bullets (lead) in .38 S&W revolvers for years, and they seem to group OK for me despite the alleged fact that they are slightly undersize for a .38 S&W bore. I have related this story before, but I will repeat it again. I have pulled .38 S&W lead bullets from numerous antique dud rounds, and have found by measurement that they run .357-.359 in diameter. So I really wonder about all the information that says .360-.361 bullets should be used, as the factories evidently did not, at least back in the old days.