The à  koda 7.5 cm Gebirgskanone M. 15 (; ) was a mountain gun used by Austria-Hungary in World War I. In German service, it was known as the 7,5cm à  koda Geb. K. M. 15. The Italians designated them as the Obice da 75/13 and the Wehrmacht would designate captured guns as 7.5 cm GebK 259(i) after the surrender of Italy in 1943.
The M15 is described by Gander and Cappellano as a howitzer, capable of delivering high-trajectory fire, which made it useful for mountain warfare. It was also lightweight, weighing and could be broken down for transport into seven loads, the heaviest one weighing over ; while the disassembled gun could be manhandled, the Germans during WWII made use of teams of mules instead. A folding gun shield could also be fitted.
The gun could fire a shell up to despite the short barrel. Ammunition types included high-explosive (HE), shrapnel, HE Shrapnel, and reportedly gas shells. According to Cappellano, the à  koda M15 proved to be superior over the lighter Cannone da 65/17 modello 13 used by the Italians.
Its development was quite prolonged, as the Austrians couldn't decide on the specifications that they wanted. Initially, they wanted a gun that could be broken down into no more than five pack-animal loads to replace the various 7 cm mountain guns in service, but prolonged trials proved that the 7.5 cm M. 12 prototype to be the best gun. However, the commander-in-chief of Bosnia and Herzegovina believed it to be too heavy and demanded a return to the 7 cm caliber to save weight. Ã Â koda dutifully built enough guns for a test battery in the smaller caliber and tested them during the spring of 1914 where they were judged inferior to the 7.5 cm guns. This cost the Austrians heavily as the 7.5 cm guns began to be delivered in April 1915 instead of the planned date of April 1914.
A standard Austro-Hungarian Gebirgs-Artillerie-Regimenter, which was used to beef up Field Artillery Regiments in some Corps, would be equipped with 36 à  koda M15s on paper, though in reality the number of guns and batteries varied quite a bit. Part of this reason was due to the slow production and dispersement of the guns and parts. 76 artillery pieces were delivered in the first half of 1915, with 250-252 barreled assemblies & 248 carriages delivered in the second half of that same year. The German Army used the à  koda as a substitute for the 7.62 cm Infanteriegeschütz L/16.5 in the infantry support role with 14 Infanteriegeschütz-battalions equipped with these guns but using more powerful HE grenades than those used by the Austro-Hungarians. While the Austro-Hungarians were generally well pleased with the à  koda, the Germans tended to use the gun in situations it wasn't designed for such as a mobile close support weapon. The M15 was designed to be disassembled for transport but the Germans often towed them on long marches as-is, so that the main parts had a tendency to become lose or disconnected after traveling on bumpy terrain. This was mainly because there wasn't a large need for disassembly on the Western Front as there were in other areas such as the Italian Front.
Serial number 1399 (manufactured 1917) is displayed in Bundaberg, Queensland, having been gifted to that city as a war trophy, in 1921, by the Australian Government.
Another, also repatriated in the 1920s, serves as a memorial to the men and women of the armed forces in Tuamarina Cemetery, Marlborough, New Zealand.