The Amazing Air Rifle of Meriwether Lewis

The “Corps of Discovery,” led by Meriwether Lewis and William Clark was one of the most incredible journeys in history. It numbered less than forty men on their expedition from St. Louis to the Pacific Ocean from 1804 to 1805. Even more amazing; they lost only one man and that was due to a burst appendix.

The Corps was vastly outnumbered, a fact that wasn’t lost on any of the Indian tribes they met along the way. Whichever one could attack this little expedition and seize their firearms would reign supreme. But the two captains had an ace up their sleeve—an amazing repeating rifle some eighty years before Christopher Spencer’s repeating rifle.

The air rifle was invented by gunmaker, Bartholomaus Girandoni of Vienna in 1780 for the Austrian Army to use against the French. While equipping the expedition Lewis purchased one at the government arsenal at Harper’s Ferry.

In his book Undaunted Courage, historian Stephen Ambrose asks the question: How could this little group of soldiers travel from St. Louis to the Pacific Ocean and back again without being overwhelmed by any of the Indian tribes they encountered along the way?

It’s a rhetorical question and Ambrose knew the answer. Lewis and Clark always met a new tribe dressed in their Class A uniforms, swallow-tail coats, with fife and drums playing. After distributing gifts Lewis would always put on a shooting demonstration with the Girandoni air rifle.

Naturally the warriors were trying to size up the little group in hopes of relieving them of their weapons. What kept them at bay? Lewis’s amazing air rifle.

The rifle could put a hole through a one-inch pine board at 100 yards. The tubular magazine held twenty-two .46 round balls and the detachable cast-iron buttstock held 800 lbs. psi air of compressed air. It required 1500 strokes of a pump to bring to full charge after which it could quietly and without smoke, fire forty times before losing noticeable air pressure. And it was fairly easy to operate. One can imagine the impression it made. Arguably, this rifle may have been the most important weapon in the opening of the West.

The captains were careful to keep their cargo a secret so the natives never knew whether they had only one air rifle or forty. And they didn’t want to take a risk on the latter. Lewis’s slight-of-hand trickery would guarantee a safe return on the incredible journey to the Pacific and back.