I've been loading the .357 SIG for four years now. I use Redding TC dies and a Redding profile crimp die in the fourth station of a dillon RL450 B(fore runner of the 550). I use Hornady 125 gr FMC for practice, and Speer 124 gr Golddots for carry loads. Best powders have been AA#7 and Alliant Power Pistol. The Power Pistol has given loads of 1410fps over my crono at 5'. This is from a 4" Glock Model32.One thing of note is that the .357 SIG headspaces on the casemouth not the shoulder as you might expect(I have no clue why they did this). Therefore a taper crimp is called for. Also don't try to make .357 SIG cases from the .40S&W, because the SIG is .020 longer than the .40 S&W. Using the Redding dies I've had no problem with bullet pull at any time.