Austro-Hungarian 7cm Mountain Gun M.99
The Austro-Hungarian 7cm Mountain Gun M.99 is a pretty typical example of the obsolete types of guns that could be found in the armies of all the warring nations at the outset of the war, and that were used mainly as a stop-gap measure, until more modern equipment could be procured. It was a gun with a rigid mount, a bronze tube and pretty primitive sighting equipment, making a sort of glorified version of the guns used during the Napoleonic Wars.
The gun was produced in some 300 copies, and when the war broke out only some 20 batteries of mountain guns were still equipped with this type. It weiged some 315kg, had an elevation of -10° to +26°, and it could fire a 4.68kg shell with a muzzle velocity of 310 meters up to a maximum range of 4.8km. (The max range should be seen as pretty theoretical, as it lacked optical means of aiming, and was obviously most suited for simple direct fire.)