I use 7828 SSC with 180 Hybrids as well for my STW. I also use Nosler brass and Federal 215M primers. But not sure how it will stabilize in your 9.5" twist. If you can get it to, it will become your favorite load.
Most people overlook the STW, but that is because most people haven't ever seen what they can do with a 180gr bullet. Working up a hot load with slow burning powder and heavy bullets in the STW is like cutting down a tree with a chainsaw, versus using an axe. It makes the extra boiler room in the case useable, and the caliber become a lot more efficient and really shines. It will make you wonder why you ever shot anything lighter than a 168 in the first place.