I'm going to load for a .357 mag. revolver with 158gr and 170 gr. bullets. I have shot some commercial bullets sized .358 and they seemed to do well. Loading the 158gr with 14 gr. of A2400 and the 170 with 13gr. Hope to increase both loads by a 1/2 gr. I don't have the tools to precisely measure the chamber throats down to a.001 ", but know they do vary. a .358 is snug in some but will pass through other with just a little force applied. The revolver is a GP100 w/4" barrel, many thousands of rounds through it since the 1990's( a lot of .38s) but still the cyl. gap has opened to .008 so think the chamber throats have eroded over time also. Might have to size them to .359? From what everybody is saying on this and different boards I will reduce the linotype to a 25% mix with 75% WW and see what happens. Thanks.