As I have mentioned here before, I went through several different powders and loads to come up with my favorite "light" Challenge Load.
I use a Berry's plated 125gr http://www.berrysmfg.com/product-i14484 ... gr_FP.aspx
over 3.7 grains of Trailboss.
Had it chronographed yesterday. After 3 shots, E was 28fps, M was 700fps, and S was 14fps
I am very pleased with this load, it is VERY accurate out of my S&W R8, soft shooting, but not so slow you have to wait to hear the plates clang.
I didn't test any other loads as I didn't know my bud was setting up his Chronograph , I was just there to shoot steel.
My old Dillon SDB seems to be loading pretty consistent so that is even better.
Funny thing is, I have shot about 4000 rounds so far with this load, and I am so used to it that I can tell if there is the slightest variance in power. It is rare, but it happens.
Carry safe and carry when and where you can. I'm just sayin'.