Post a pic of the HP cavity of the bullet.
I bet those BB loads in the pic are using the 9mm Gold Dot bullet and not the .357sig Gold Dot bullet. Profile is different on the .357sig GD as well as the actual HP cavity.
If you want a very good .357sig load that can be chambered many times with no setback, get some Federal HST. Feeds silky smooth.
Maybe I missed it but Im just curious...how do you dispose of it properly?
Who could you take it to?
My setback roads I either break up for components or knock the bullet out past correct OAl with my bullet puller and then seat/crimp the bullet to proper depth. Then shoot it at the range.