The advantages of the rifle were a high rate of fire, no smoke from propellants, and low muzzle report. In addition to having a 19, (plus one in the chamber), round capacity of .46 caliber balls in an internal tubular gravity-fed magazine. The velocity was equivalent to that of the .45 ACP cartridge. It was fired by utilizing a detachable air reservoir, which was capable of around 30 shots. It took nearly 1500 strokes of a hand pump to fill the reservoirs. which of course helped lead to its demise. Even though a wagon-mounted pump had been made available later.
So next time an anti-rights person declares that the founders had no idea of the kind of arms that we would have today. You can let them know with confidence that they [once again] have no idea of what they are talking about.