From Aymette v. State of Tennessee, 2 Humphreys 154 (Tenn. 1840):
"The words "bear arms," too, have reference to their military use, and were not employed to mean wearing them about the person as part of the dress ... A man in the pursuit of deer, elk, and buffaloes might carry his rifle every day for forty years, and yet it would never be said of him that he had borne arms."
As pointed out in the link I provided Lawrence Tribe, who is no conservative by any stretch of the imagination believed the Founders were referring to defense of one's life, family, and property. That is at least partly why he changed his opinion regarding that amendment's meaning.
Still even if the word "bear" was meant strictly for military use when needed as that state court decision seems to believe it doesn't preclude the people from keeping arms. Again under your theory if the 2nd Amendment were only about militias and using arms for that purpose then theoretically all of us could be forced to keep our arms locked up somewhere under state supervision until needed. Why do you suppose that wasn't advocated from the very beginning when the Amendment was adopted?