Well, that's really astounding.
There's no way that data could be right. 13.0gr AA9 under the 124gr bullets is the "legendary" load for the Sig. It's virtually every official source's max and it's a compressed charge, which helps prevent bullet setback.
That 14.6gr load is nearly impossible. I'm not sure you could even seat a bullet.
QuickLoad thinks it would be a 122% compressed charge.
QuickLoad seems to think AA9 is faster than most data shows but even if I adjust the burn factor of so that 13.0gr matches the max pressure, which also brings it close to the predicted velocities, it still thinks 14.6gr is between 69,000 and 75,000psi, depending on the exact bullet.
I may have to write to Speer and see what they say.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.