I use nothing but Longshot on 40sw for all my 40cal guns. I can achieve factory level velocities on all at 25k psi or less. velocities e.g.,
NOS135jhp 1250, MG155jhp 1130, and MG180jhp 1009fps. It may not be the most accurate load in the world, but the low pressures give me a warm feeling. If you want to (and I did once) you can load the 40's up to very near 10mm velocities with LS--e.g., 1160fps on MG180jhp from a Sig 226, and still supposedly be below SAAMI max. Too many war stories on 40sw KB! for me, tho. And You'll still need to change your spring if you really want to shoot this stuff more than once or twice.
You can get the load data from Hodgdon web site.
Another medium load at low pressure I like is 7gr Unique under the MG155jhp. COL 1.135". You get low 1100's.
And Oh yeah, I don't use R-P brass for 40 anymore. The brass is too thin and doesn't grasp the bullet as well as most others. I prefer Speer, Federal and Starline.
YMMV
dave