LOL...because energy doesn't kill. The .45/70 has considerably more frontal area on the bullet than the .308. It makes a big hole that does lots of damage. Big holes are very desirable in close range encounters with a bear.
If it was all about energy, a 25-06 would be a way better choice than a .45-70 but I know which one I'd rather be holding. But then again, I don't believe energy kills as well as big holes...
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