It doesn't matter. Either will work fine in the rifle. I will pay a little extra to get ammunition made in the United States because I'd rather employ our people.

Check with the range you are going to and see what their requirements are.

If you don't reload, steel case ammunition is generally cheaper and will not harm your gun.

If you (or a friend) do reload (or are thinking of getting into it), then you want to pay the little bit extra to get boxer primed bass cases that can be reloaded.