I just set up to reload 9mm, I normally load 45acp and I am really a newb at that. I was hoping to simply load with the same W231 I'm currently using for the 45's. But my Hornaday book says W231 for 115g only, 124, 147, will need a different powder. I have two questions, why?, and could you suggest a good powder for starting out? I have purchased 2500 115g bullets, so W231 will work for now. But is there something better I should look at?