This goes back to how hard the bullets are. Fast powders for hard bullets in low pressure rounds. That way they obdurate better, faster.

For the 40S&W, I have only two powders that I would ever use, well, maybe 3, but that is because all of my 40's are not fully supported.

The fastest that I would ever use in one like I have is Unique, not that I would use it, just nothing faster. My first choice, especially for lead, SR4756, hands down. The only thing that gives better performance, and that is with jacketed, is Longshot. Lowest pressure, highest velocity.


Pick something between the suggestions and go for it. Unique to Longshot. Lots of good powders in there!