Does Belt Mountain (now sold by Grizzly) offer their brass solid for reloading at all? If not what would be an obtainable bullet that performs similarly? Hard cast gas checks? Barnes Buster? Perhaps something from Cutting Edge?

Don`t know if its true but I once heard that Grizzly will sell the Punch bullet as a reload component. A quick call to them will find out.
The Barnes Buster is another fine deep penetrating bullet. Cutting Edge offers a full line of solids but I don`t have enough field experience, at this time, to give an opinion. I know there are members here with much more experience taking big game with cast bullets then I. Perhaps they can share their knowledge. Sixshot comes to mind as a true cast bullet, big game handgun hunter and I know there are others....
PS- the photos show game I`ve taken with the Punch bullet...