By Tim Bean

There’s a good chance Lewis and Clark would have faded into a fog of mystery had it not been for the “miracle rifle” they carried on their 5,000 journey.

The Corps of Discovery Expedition set out in 1804 to map the newly acquired Louisiana Purchase, which would later become the Midwest and Western United States. With no maps, no GPS, and no real idea what awaited them in undiscovered America, Lewis and Clark’s entourage plunged into absolute wilderness for the sake of science, economy, and good ol’ curiosity. The greatest unknown—and the primary concern of the expedition—were the pockets of Native-Americans they would no doubt stumble across on the journey west.


Lewis and Clark’s solution for establishing (relatively) amiable relationships and trade with Native-Americans was simple novelty. Along with their provisions and weapons, they also carried quantities of “souvenirs” marking the expedition’s passage. These included ribbons, mirrors, and assorted trinkets, as well as a quantity of Jefferson’s Peace Medals. Each exchange also brought a brief cultural exchange, in which Lewis and Clark would display and demonstrate their Western technology. It was here that Lewis’ Girandoni Air Rifle shined.

Designed in 1779, the Girandoni Air Rifle was fickle, delicate, and expensive, but no rifle on Earth could exceed this air rifle in tactical performance.

*Although I have read several conflicting reports on the effectiveness of the Girandoni Air Rifle, I am relying on the expert assessment of Phil Schreier, Senior Curator of the National Firearms Museum…because he’s the senior curator of the National Firearms Museum.

Consider its chief contemporary, the Model 1795 Musket. Designed by famed inventor Eli Whitney, this smoothbore stood as the benchmark military firearm at the time of the Corps of Discovery Expedition. This muzzleloader fired a .65 round ball at over 1200 ft/s, with a practical range of 50 to 75 yards (for the uninitiated, that makes a BIG hole). An experienced soldier could fire approximately three rounds per minute. For the technology of its day, it was a fine, dependable firearm and saw use in combat as late as the American Civil War, over six decades after its design.


The Girandoni Air Rifle propelled .46 caliber lead balls at 500 ft/s with an effective range of roughly 100 yards. Each air reservoir, which replaced the traditional blackpowder, provided propellent for 30 rounds, and each rifleman carried three air reservoirs. An experienced user could fire ~20 rounds in 30 seconds, thanks to its ingenious spring-loaded feed. It produced no smoke—a frequent problem for muskets, since smoke both clouded a soldier’s vision and pinpointed his firing position—and had a gentle muzzle report. Unlike a muzzleloading weapon, a soldier didn’t need to kneel or stand to reload, allowing them to maintain better cover.

“[Lewis] shot his air gun, told them that their was medician [sic] in hir [sic] & that She would doe [sic] Great execution, they were all amazed at the curiosity, & as Soon as he had Shot a fiew [sic] times they all ran hastily to See the Ball holes in the tree”

~From the journal of Second Lieutenant William Clark

This air rifle had less than half the muzzle velocity of a smoothbore musket, so the great debate today is whether or not it was painfully underpowered. Senior Curator Phil Scherier reports that during a test of an EXACT replica of a Girandoni Air Rifle, its accuracy was superior and its round balls “will put a hole completely through a one-inch pine board at one hundred yards.”

That’s an effective weapon.


Lewis’ “air-gun” demonstrations became a routine part of the expedition, and displayed their rifle’s accuracy, silence, and power. Native-Americans were very familiar with contemporary firearms at the time (many even owned them) but no tribe had a weapon like this. It came across as a novelty, but also as a friendly warning for any ambitious parties. Lewis and Clark carefully secured and protected their collection of provisions and equipment, leaving tribes to assume the group didn’t have just one air gun, but dozens of them.

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Lewis and Clark had many reasons for carrying only a single Girandoni. Since gunsmiths made each air gun individually, it cost a small fortune to purchase and repair. The air reservoirs were made of thin, leather-covered iron, riveted and brazed, and were delicate even when empty. When full, they held air at hundreds of pounds per square inch of pressure; even the slightest puncture would rupture them. This also prevented the attachment of a bayonet on the rifle, an essential component of 18th and 19th century combat. Hundreds or thousands of pumps by hand were needed to refill each reservoir as well, so the rifle couldn’t be used in sustained combat.

The Girandoni Air Rifle was indeed a “miracle rifle” of its day, so unique and original in effectiveness and design that it bordered on science fiction. Lewis and Clark took advantage of this technological wonderment not to intimidate Native-Americans they met on their long journey, but to project an aura of benevolent strength. How large a part this rifle made in easing the hardships of the expedition is something for historians to debate, but there’s no question the party considered it essential: it’s mentioned in dozens of Clark’s journal entries. It may have contributed to the most amazing feat of the expedition: of the 45 party members, only one died during their voyage—a natural death of appendicitis.

Want to Know More? 

If you’re a Lewis and Clark junkie, then here’s your fix: an annotated, searchable collection of the expedition’s entire journey online at Journals of the Lewis & Clark Expedition, expertly curated by the University of Nebraska Lincoln.