Scout- I chose the 45-70. You can buy factory ammo practically anywhere, components (if you reload) are readily available, and theres no end to the loading data available. 45-70 brass is much cheaper and more available than .450. The only advantage to 450 is that it's factory ammo comes already hotrodded. I don't believe I've ever bought factory ammo for my 45-70 anyway. My factory is in my basement.