Just purchased a new Lyman 356637 4 cavity, drops perfect bullets, but I can't seem to get them to stabilize in any of my 9mm pistols. Wondering what I may be doing wrong here. My lyman cast boolit manual does not even list this mold so having a bit of trouble with load data, so far I have only tried 3.0 and 3.5 grains titegroup. Have tried sizing to .356, .357, and .358 seated to 1.100 chambers and feeds perfect. Almost every round is keyholed. Not stable at all. I have cast and shot many thousands of rounds but this is the first time having any trouble. 3 different pistols, CZ75SP01 Shadow, Smith and Wesson M&P, and Glock 9mm, none of these pistols will shoot the lead worth a darn, but all shoot jacketed 147 grains perfectly.
I have also tried these bullets at .358 with 4 grains of Win 231 in my Ruger GP100 38 special, shoots perfect and very accurate. I must be doing something wrong. Any Ideas? Other powders? Thanks.