David Kopel.

While the Founders could not foresee all the specific advances that would take place in the nineteenth century, the Founders were well aware that firearms were getting better and better.

Tremendous improvements in firearms had always been part of the American experience. The first European settlers in America had mainly owned matchlocks. When the trigger is pressed, a smoldering hemp cord is lowered to the firing pan; the powder in the pan then ignites the main gunpowder charge in the barrel.

The first firearm more reliable than the matchlock was the wheel lock, invented by Leonardo da Vinci. In a wheel lock, the powder in the firing pan is ignited when a serrated wheel strikes a piece of iron pyrite. The wheel lock was the first firearm that could be kept loaded and ready for use in a sudden emergency. Although matchlock pistols had existed, the wheel lock made pistols far more practical and common. Paul Lockhart, Firepower: How Weapons Shaped Warfare 80 (2021).

The wheel lock was the “preferred firearm for cavalry” in the sixteenth and seventeenth centuries. Id. The proliferation of wheel locks in Europe in the sixteenth century coincided with the homicide rate falling by half. See Carlisle E. Moody, Firearms and the Decline of Violence in Europe: 1200-2010, 9 Rev. Eur. Stud. 53 (2017)

However, wheel locks cost about four times as much as matchlock. Moreover, their moving parts were far more complicated than the matchlocks’. Under conditions of hard use in North America, wheel locks were too delicate and too difficult to repair. The path of technological advancement often involves expensive inventions eventually leading to products that are affordable to average consumers and are even better than the original invention. That has been the story of firearms in America.

The gun that was even better than the wheel lock, but simpler and less expensive, was the flintlock. The earliest versions of flintlocks had appeared in the mid-sixteenth century. But not until the end of the seventeenth century did most European armies replace their matchlocks with flintlocks. Americans, individually, made the transition much sooner. Lockhart at 106.

Indian warfare in the thick woods of the Atlantic seaboard was based on ambush, quick raids, and fast individual decision-making in combat—the opposite of the more orderly battles and sieges of European warfare. In America, the flintlock became a necessity.

Unlike matchlocks, flintlocks can be kept always ready. Because blackpowder is hygroscopic, and could be ruined by much water, it was common to store a firearm on the mantel above the fireplace. Another advantage, which mattered greatly in America but was mostly irrelevant for European warfare, is that a flintlock, unlike a matchlock, has s no smoldering hemp cord to give away the location of the user. Flintlocks are more reliable than matchlocks—all the more so in adverse weather, although still far from impervious to rain and moisture. Significantly, Flintlocks are much simpler and faster to reload than matchlocks. See, e.g., W.W. Greener, The Gun and Its Development 66-67 (9th ed. 1910); Charles C. Carlton, This Seat of Mars: War and the British Isles 1585-1746, at 171-73 (2011).

Initially, the flintlock could not shoot further or more accurately than a matchlock. Lockhart at 105. But it could shoot much more rapidly. A matchlock takes more than a minute to reload once. Id. at 107. In experienced hands, a flintlock could be fired and reloaded five times in a minute, although under the stress of combat, three times a minute was a more typical rate. Id. at 107-08. Compared to a matchlock, a flintlock was more likely to ignite the gunpowder charge instantaneously, rather than with a delay of some seconds. Id. at 104. “The flintlock gave infantry the ability to generate an overwhelmingly higher level of firepower.” Id. at 107.

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In 1777 in Philadelphia, inventor Joseph Belton demonstrated a firearm that could fire 16 shots all at once. The committee watching the demonstration included General Horatio Gates, General Benedict Arnold, and scientist David Rittenhouse. They wrote to the Continental Congress and urged the adoption of Belton guns for the Continental Army. Congress voted to order a hundred–while requesting that they be produced as 8-shot models, since gunpowder was scarce. However, the deal fell through because Congress could not afford the high price that Belton demanded. Repeating arms were expensive, because their small internal components require especially complex and precise fitting.

Hence, the Founders who served in the Second Continental Congress were well aware that a 16-shot gun had been produced, and was possible to produce in quantity, for a high price. Delegates to the 1777 Continental Congress included  future Supreme Court Chief Justice Samuel Chase, John Adams, Samuel Adams, Francis Dana, Elbridge Gerry, John Hancock, the two Charles Carrolls from Maryland, John Witherspoon (President of Princeton, the great American college for free thought), Benjamin Harrison (father and grandfather of two Presidents), Francis Lightfoot Lee, and Richard Henry Lee.

Likewise, the 22-shot Girardoni rifle famously carried by the Lewis & Clark expedition starting in 1803 was no secret, as it had been invented in 1779. It was used by the Austrian army as a sniper rifle. Powered by compressed air, its bullet his as hard as the modern Colt .45ACP cartridge. John Paul Jarvis, The Girandoni Air Rifle: Deadly Under Pressure, Guns.com, Mar. 15, 2011.

The Girardoni had a 21 or 22 round caliber tubular magazine, and could be quickly reloaded with 20 more rounds, using speedloading tubes that came with the gun. After about 40 shots, the air reservoir could be exhausted, and would need to be pumped up again.

As of 1785, South Carolina gunsmith James Ransier of Charleston, South Carolina, was advertising four-shot repeaters for sale. Columbian Herald (Charleston), Oct. 26, 1785.

Visit his article for further discussion of innovation, as well as the founders in literature and their own positions on development of weapons.

Suffice it to say that the founders would have been delighted with massively powerful and rapid firing weapons for the purpose of effecting quicker victory in the war of independence.

Also, note that innovations (except for crew served) almost always come from the civilian sector, even today.  The 30-06 was a civilian round before it was used in the original M1.  The .308 was introduced to the civilian market 2 years before adoption as the 7.62 by NATO.  Even Stoner adopted (and adapted) a mostly civilian equivalent for his 5.56 round in the M16, and the AR-15 was introduced into the civilian market before it was ever adopted by the U.S. military.

Revolvers have been in existence for a very long time, and yet were adopted as one of the sidearms by the U.S. and British militaries and in use up through WWI and even a bit beyond (M1917).  The venerable 1911 design by JMB may be the exception to the rule, having been designed for use by the military.

Don’t allow anyone to tell you that the founders would have felt differently about the second amendment had they known culture today.  They’re just being emotional and ignorant.  The founders would have said to spank the children and send them back to the schoolmaster to learn the bible, letters, mathematics and logic.