The reason Hornady shortened the case of the 45-70 (and other Leverevolution offerings) is not a throat issue, but an OAL issue. The 325 gr LE bullet is too long past the nose to function in a lever rifle if loaded in a standard 45-70 case. I believe you can load that bullet in a standard 45-70 case and fire it with no problems in a single shot 45-70. Otherwise, I doubt Hornady would offer them as components.
I suspect the same is true for the Barnes 400 grain semi spitzer. If not, you can always stuff it a little further in the case to fit the throat. I dont believe that bullet has a crimp groove anyway.
If you really want a spitzer, why not get the Barnes X offerings. They are about the same price, and have better BCs.