Whenever the issue of gun-control is raised, you can, with absolute certainty, count on some poorly educated liberal to trot out the "our forefathers could not have possibly foreseen the destructive potential of future weapons" argument.  That is to say, the Second Amendment means we may constitutionally own only muskets (and that only if we are part of a regulated militia).

This is an affirmative statement that the speaker ought to be capable of supporting.  Yet, as is so often true of the liberal worldview, no liberal will offer any support for it -- because he cannot, and he cannot because it is simply not true that the Founding Fathers lacked imagination when it came to weapons.  In fact, all they had to do was examine weapon development within their own lifetimes.

At the time of the Revolutionary War, the American long rifle, one of the earliest guns to stabilize a projectile with a rifled bore, had really only come into its own a half century before, although its first use was in the very early 1700s.  Achieving a longer range than the usual infantry-issue musket of the day, the American long rifle was used to harass British troops during their retreat through New Jersey, assured more favorable conditions for the Continental Army during the Battle of Saratoga, and proved decisive during the Battle of Cowpens, when Morgan's Riflemen fired three volleys before the British muskets came within range.  Morgan and his sharpshooters then undertook a planned retreat to another position and fired another three volleys.  By the time Morgan's company joined the main force, the British were disheartened by their losses and inability to respond and quickly fell into retreat.

But the Americans weren't the only ones inventing and adapting.

The Ferguson Rifle was developed by Patrick Ferguson for the British Crown and given an English patent in December 1776, the same month when Washington crossed the Delaware and took Trenton.  It was a breech-loading rifle, one of the first that the British military tested, and was said to be capable of firing six to ten rounds per minute in capable hands.  It was used at the Battle of Saratoga in Ferguson's Experimental Rifle Corps and at the Battle of Brandywine.  Although production problems and high cost plagued the development of the Ferguson Rifle, its unique design allowed for a rate of fire at least twice that of the Brown Bess, with an effective range of 200 to 300 yards.  By comparison, the Brown Bess, which was used by both the American and British military forces, was accurate between 50 and 100 yards.

The British were also involved in an arms race with some Continental powers for purifying and improving gunpowder mixtures.  In France, the work of Antoine Lavoisier as the Commissioner of the Royal Gunpowder and Saltpeter Administration led to improved understanding of the nature of gunpowder and its potency.

Technological advances were not limited to the field of firearms, either.

David Bushnell was a Yale College freshman in the 1770s.  A young inventor, he had turned his attention to underwater explosives after he had proved that gunpowder could be detonated inside a sealed device.  He is best remembered as the inventor of the first submersible vessel, the American Turtle, which was intended to attach such a device to the hull of an enemy ship and then be detonated with a clockwork trigger, another of Bushnell's inventions.  It was undergoing field tests in the Connecticut River in November 1775, although the British had been informed that it was about to be deployed in Boston Harbor.

A cork saturated with a bioluminescent fungus illuminated the Turtle's interior, but this light would fail at low temperatures.  Benjamin Franklin was asked to provide some alternative light source, but when none was brought forward, the Turtle was dry-docked for the winter.  By the time it was ready to be deployed, General Howe had removed his fleet from Boston Harbor.  Bushnell then offered the Turtle to General Washington, who, although skeptical, continued to fund the project.  After a failed attempt to sink the HMS Eagle off Governors Island, the Turtle was sunk while sitting on its tender vessel.  Bushnell, however, continued his work with underwater mines.

Given these advancements in weapon technology, it simply cannot be believed that the men who wrote the Second Amendment were unaware that firearms would change over time.  They knew as part of their war effort that guns would increase in range, speed of discharge, and power, and that submarines, mines, and mechanically operated triggers were coming.  They may not have been able to draw an AK-47 or design its operation, but they knew that somebody would.  To believe that they couldn't imagine such developments can be attributed only to a modern arrogance and our own lack of imagination.