Let's say the Miller case came back to the USSC with the finding that this weapon (the SHOTGUN) was indeed used by militia. Do you think the USSC would have interpreted the second amendment to allow this militia weapon to be owned and used by Mr. Miller outside the confines of a well regulated militia? (ie., for personal use?)
And what makes you think that?
The fact that personal use of a weapon makes a person all the more competent to use it in a militia situation?