There are a bunch of conicals you can try to see if they work - maxi balls, maxi hunters, PA conicals, etc. and patch and ball. I don't recall the twist rate of the Firestorm but if its faster than 1:48 you may have accuracy problems with the RB.
By the way, how is the trigger on your Firestorm. I know a guy who got one and had a heavy trigger. He tried to weigh the trigger pull and it bottomed out his scale.
ps: be careful you don't fall out there on the ice. I'll be hunting PA too. I might just see if I can find some ice cleats for my boots this weekend. And I think I will hunt the bottom of the mountains cause that is where I think the deer will be either by choice or that's where they ended up from sliding down.