OK. The norma brass would be good to go. The .473" chamber wall is still a very generous chamber. Shiloh uses .468". My .44-100 chamber has a .464 and that is still loose with the Jamison and Starline brass I use, but mine wont except a GG. If your using a GG with the Norma brass your good to go for a GG.
My .44-100 reamer is to small in the base @ .500" and neck @ .464" for you to use to make your chamber a .44-100 rem. Sorry I cant help.
Jason must have read this post

I got a schedual. May and Oct will work for me. That will be a good warm up for Backer and the Q.