124 grains at 1350 fps is too warm for my blood, bro, for the following reasons:
--I ain't no ballistician, but that sounds big time over-pressure to me for 9X19. 1350 is hot but safe for a 115 grain bullet.
-- I'm not awre of any such load ever having been used in a shooting. In this day and age, I see no reason not to carry something "street proven."
-- .357 SIG bullets by major manufacturers are geared to the caliber's high velocity. A 9mm 124 grain driven faster than its designer's velocity parameters could disrupt prematurely, adversely affecting penetration.