Get a reloading set up first. Then, any caliber you want is a set of dies and a handful of brass away. If you are so inclined, a full reloading set up from some of the mail order places can be had for under a hundred bucks. The cost of 500 or 45-70 ammo gets prohibitive if you do much shooting at all. Reloading won't save any money, cause you just shoot more. That's the point though. You can also tailor loads for the application. Full bore 500 loads aren't any fun to shoot, after the third one. A light load with Titegroup and a 300-400 gr cast bullet is another story altogether. They are a hoot watching those big old holes come into the paper, and much easier on the shoulder. I love my 500, but shooting factory loads only would take a lot of the fun out of it. I'm so far gone in the hobby, I even cast my own projectiles. Get the 500 and enjoy it. But there is a law, you HAVE to get a 45-70, and a 30-30 to go with it.