Both work. You can find more Bushmaster ammo right now because it works well in the AR platform (where I have several). More than adequate for deer out to 200. After that, it falls like a pumpkin. Hornady has a 245 and 250 load.
If you hand loaded, I'd tell you to do the 45-70. It is more versatile, and you could load it from mild to wild in the Ruger #1.
This...But I'll add both are way overkill for deer.