SR4756 is a "go to" powder for me. I use it in heavy 38spl, medium 357mag and regular 40S&W cartridges.

There are very few powders that will give you the velocities that it gives in these calibers. The other caveat is the pressure you get when achieving those loads. While I have no pressure testing equipment per se, when looking at the Hodgdon/IMR/Winchester data, (and their data was pressure tested) it almost always gives the lowest pressure for a given load.

I haven't used SR4759. I have used SR7625 and have no real need for it.

SR4756 is also the propellant used for "THE LOAD", just to throw that in there!