Whatever the product number is for the .357sig 124gr XTP Hornady Custom load is, that is what had the different non 9mm bullet. I only have first hand experience with the 124gr XTP factory loads. I am currently out of them, shot them all. I bought several 100ct boxes of 90gr, 115gr and 124gr XTPs and they all have a different nose shape and HP cavity than what cam loaded in Hornadys 124gr sig ammo.
Speer GD 53918 (left) Hornady Custom 124gr XTP .357sig factory load (right)
Speer GD 54234 (left) Hand Load 100ct boxed 124gr XTP (right)
The 9mm version that comes in the 100ct boxes for reloaders obviously has a smaller metplat, more side angle and the hp cavity is deeper and more cone shaped. The .357sig XTP is closer to the shape of the GD with a larger metplat and a shallower more dish shape hp cavity. Also notice the cannelure on the sig XTP which the 9mm version does not have. The cannelure helps to hold the jacket together. The sig HST bullet has a cannelure as well.