Reportedly, less than 1,500 Austrian military Model 1780 Girardoni repeating air rifles were manufactured in Penzig, Austria, and most notably used by Austrian sharpshooters in military service circa 1780-1815; only less than 25 of these rare military pattern Girardoni rifles are known to exist today. The Girardoni (sometimes spelled "Girandoni") is easily the most famous early air rifle, or "windbuchse," largely thanks to the fact that for many years it has been associated with Lewis & Clark and their famous Corps of Discovery Expedition. It is widely believed that Meriwether Lewis carried either a Girardoni or a very similar design by Isaiah Lukens of Philadelphia. The expedition carried some advanced weapons of the time to display their military firepower, in which they performed demonstrations in front of Native American tribes, including with a "magic" airgun. This extremely rare Austrian military Girardoni repeating air rifle offered is of the exact kind believed to have been possibly carried on the Lewis and Clark Expedition, making this a highly desirable rifle today that would be a prized centerpiece in any advanced firearms collection or Americana collection, and is worthy as a prominent display piece/attraction in any museum. Page 599 of the "Blue Book of Airguns, Thirteenth Edition" has another example of an Austrian Military Model 1780 Girardoni repeating air rifle (not this example offered) photographed above the caption, "There is strong evidence in the Lewis and Clark Expedition journals suggesting that this specimen is the air rifle carried on the Lewis and Clark Expedition. Many arms and historical experts consider the Lewis Airgun, ca. 1790, as the world's most important and most valuable airgun." The Girardoni was designed by Bartolomeo Girardoni around 1779 and is also significant as one of the first widely used repeating martial arms, with a magazine tube on the right side of the barrel for use with lead balls and a breech block that is able to be pressed sideways against spring pressure for loading/repeating capability. These advanced air rifles were considered to be far ahead of their time when compared with the muzzleloading flintlock long arms then the standard in widespread military use. Because the air tanks took around 30 minutes of pumping by hand to bring to full pressure, the riflemen had assistants that repressurized the reservoirs initially and later also had more efficient wagon mounted pumps. These rifles were reportedly capable of approximately 30-40 shots on a single filled tank (one source claims more than 60), although original instructions to Austrian soldiers advised them to only fire one loaded tube of 20 balls before switching to another fully charged air reservoir due to loss of power as the air tank loses pressure. To reload the tube magazine, the user opens a plug at the front of the magazine and empties a “speed loader” into it. The well known British military Ferguson breech loading flintlock rifles of the same time period were capable of about 6 shots per minute, which was considered quick when compared with the then standard muzzleloaders of the time, whereas the Girardoni was capable of at least 40 shots per minute with a skilled operator. With a muzzle velocity of about 600 fps using a .46 caliber ball weighing around 146 grains, their effective lethal range was between 125-150 yards when properly charged, which would have been devastating on the receiving end when combined with its repeating capability. "Wind guns" had several advantages over conventional firearms including that they were quieter, smokeless, quicker to reload, and relatively unaffected by rain. They also required less cleaning since they did not require corrosive black powder. This Austrian military example is chambered in .46 caliber/11.5 mm and features an octagon barrel with 12-groove rifling, dovetail mounted blade front sight and notch rear sight, 20-21 shot gravity-fed tubular magazine, screw-off metal buttstock air reservoir, and a walnut forearm with incised border carvings. Austrian military eagle stamp located on top of the breech of the barrel and on the front flat of the threaded section of the stock reservoir, a "G" Girardoni maker marking is stamped on top of the brass receiver body and on the stock reservoir, along with an unknown tree-like symbol (possibly acting as a "1") ahead of "382", with the same tree-like symbol ahead of "263" on the stock reservoir, and a fleur-de-lis is stamped on the left of the stock above the sideplate. More information on Girardoni air rifles can be found on pages 598-601 of the book "Blue Book of Airguns, Thirteenth Edition", as well as in the online articles at https://www.beemans.net/Austrian%20airguns.htm and https://www.beemans.net/lewis-assault-rifle.htm where the "Lewis Airgun" is shown in detail.