I just got a Lyman 358432 WC mold.It has 3 drive bands and no crimp groove.It is my understanding this mold was made for 38 auto pistols.I intend to use it in a S&W 686-3.The question i have is do i need a crimp?How would i crimp this Boolit?I intend to run these with a very light load.Any thoughts on a good powder would also be helpful.Thanks.