As we all know, there has been some controversy concerning the pedigree of the common Girandoni Austrian Military Airguns: The gun seen in Backer/Currie. (AMA)

There was one side that maintained, for good reason, that these had to be AMA's because of the G. XXX and double eagle markings.

On the other side it has been stated that these G. AMA did not match the only known specs of the original M1780 and, more important, they're obviously of English manufacture.

What nobody ever considered was that both statements could be true; that these guns could be manufactured in England for the Austrian army. Which is exactly what I think happened.

During the wars against France and Napoleon, England sent economic and military subsidies to Austria including guns manufactured in England for Austria.

There is actually a lot of evidence that instead of one Girandoni model there are actually two models: the original M-1780 Girandoni and the later "MKII" G. gun manufactured in England.

The Austrian army kept the use of air guns in their tactical texts on defense of fortified positions as late as 1862. Clearly, they could not be thinking of the original M-1780 model in 1862.

What kept this a bit of a secret is that the Austrian army division requesting air guns was by the k.k. Genie-Korp. The Genie-Korp are the miners and sappers. These are the guys in command of the defense of forts. It is specifically for the defense of fortresses, and underground warfare, that the Girandoni MKII was used by the Austrian army.

Was the Girandoni MkII used against Napoleon? Absolutely, yes. Graz- Schlossberg, 1809. The Austrian commander in charge of defense of the Schlossberg (Castle Hill) fortress was k.k.. Genie-Korp Major Hackher. His reports include 24 air gunners before that start of the French actions. After surrendering, the armory inventory -required by the French Command from the fortress- includes 6 air guns. Chances are, that those 6 air guns would have been G. MkII versions made in England.