Identifying

[DonVoigt]

The expanded cartridge won't reach the rifling.
The no extract is due to the fact that there is little recoil, as the the .30 slug in a .357 bbl builds almost no pressure.

It can't recoil enough to extract or eject.

The bullet will do no damage to the rifling, even if it hits it.

I'd say no harm done, just clean the chamber and barrel well and proceed.