You have the right to own a musket and make the musket balls in your house.

[liberal N proud]

50. New technology that was not widely accepted or understood by those who ratified the 2nd amendment

The general weapon of the day required the shooter to reload between shots giving time for the target to retaliate or flee.
This new technology was used by very few and unlike today, was not quickly proliferated through out the general population because they either were yet not informed of it or could not afford to move to the new technology quickly.

You are talking about the next great breakthrough in weapon technology 1791, a time when technology was slow to be integrated or accepted. Most of the weapon owners of the day understood only the prevalent technology of the day and did not have the NRA Magazine or other publication that focused on new gun technology.

When people purchased weapons in 1790, it was primarily for hunting to eat and occasional protection from wild animals. The most common guns in the Civil War:
32 Colt 1849 - loaded with loose blackpowder and a bare bullet, referred to as "cap and ball,"
32 S&W No. 2 - Loaded much faster, 10 or 15 seconds with experience, then two minutes to load the much more common cap and ball revolvers
36 Colt 1851
36 Colt 1862
44 Colt 1860
44 Remington
58 Springfield Musket
577 Enfield Musket
Burnside Carbine
Colt Walker & Dragoon
Confederate Pistols, Carbines, & Shotguns
Henry Rifle 1860
Sharps Carbine
Smith Carbine
Spencer Carbine
Less Common Guns of the Civil War
Artillery

Most weapons used in the 1860's were still single up to 6 rounds then required reloading. Long after the ratification of the 2nd amendment and the introduction of the repeaters mentioned. Most people still relied on single shot weapons and they still wreaked havoc during the Civil War.

The point is we don't need weapons that can fire off 30, 90 or 100 rounds, becoming killing machines.