I have found a 2 PF diference between my g17 and g34 with the same load. And that same load did not make the powder floor on a SW MP. It is best that you work up your own loads with a chrony.Y our short barrel will benefit from a faster powder. Ive used BE and 231 and they work very good witn 124 Lead. I have also tried WST and it is also a good choice. Its lighter color is a plus for begginer reloaders. If you are getting serious about competing, it is important that you learn your powder's behavior in different temp. conditions, and load accordingly.