There are a couple of tried and true ways to deal with the problem of bullet setback:
1. Use an asphaltic sealer when seating the bullet, which will actually glue the bullet into place (also gives the benefit of waterproofing the neck).
2. Use a cannelured bullet and a crimp. This isn't a problem with the .357 Sig, as I'm pretty certain that the case headspaces on the shoulder, not the case mouth.
3. Use a 'stab' crimp that actually dimples the case into the bullet. This damages the bullet, though.
4. Use a stab or roll crimp on the case just BELOW where the bullet sits. This only works, though, if there is enough case neck to do the crimp on.
