One of the arguments prohibitionists, and even those who wouldn't be inclined to prohibitionist if they were more informed, often ask why would an average man need to own an assault rifle? Sometimes they might even say that the 2nd amendment doesn't protect the assault rifles from confiscation because the founders would have had no idea about the weapons we would have today. The logic is foolish, and dangerous, considering that it could be extended to our other liberties expressly protected in the constitution, and it is somewhat insulting to our founders, they lived in an age of rapid scientific discovery. They saw the discovery of electricity and the beginnings of the industrial age. I find it doubtful that the founders didn't anticipate new weaponry being invented and accessible to the people.
Even then it didn't matter. As the founders were concerned about liberty, and they new that if the discrepancy between the people and the state ever became to large that tyranny would result. One man, someone who you probably haven't heard of, made their views on the matter abundantly clear. He was a member of the continental congress, the group that drafted the constitution:
"Congress have no power to disarm the militia. Their swords, and every other terrible implement of the soldier, are the birthright of an American... The unlimited power of the sword is not in the hands of either the federal or state government, but, where I trust in God it will ever remain, in the hands of the people" (Tench Coxe, Pennsylvania Gazette, Feb. 20, 1788)
Tench Coxe makes it abundantly clear that Americans are have to have the weaponry available to the soldiers in the military of the United States available to them. The ability to own, carry and use an assault rifle, and whatever future weapon is invented, is our birthright. It is how we secure our freedoms, and can honestly call ourselves a free man. Because a man disarmed is not truly a free men but a man whose liberties simply privileges extended by his betters.