The ammunitionartifacts.com website list two 45-75 loadings available. The one for "original" 1876 Winchester rifles uses the Magtech 32 gauge brass as the basis for it. Their 45-75 "reproductions (read Uberti etal)" uses the 50 Alaskan brass as the basis for it. He claims the difference in rim diameter is why he uses the different brass cases for the two versions of 45-75, original and reproduction guns. That is why I have asked if anyone had tried the 50 Alaskan. The head, if specifications can be believed, is close to the Jamison 45-75 that works well in my Cimarron/Uberti. Its cheap enough I was thinking about ordering 20 rounds and seeing if I can form 45-75 out of it.