The difficulty of deploying artillery in New Guinea led to a need for a gun which could be broken down into light parts and transported by aircraft or jeeps. The Army had only a small number of British 3.7 inch Mountain Howitzers, and Australia's request for United States M116 75mm pack howitzers was not immediately filled. In September 1942, the Army's Director of Artillery, Brigadier John O'Brien, suggested that a variant of the 25-pounder be developed to meet this requirement. This proposal was agreed to, and all development work was conducted in Australia by the Army, the Ordnance Production Directorate and Charles Ruwolt Pty Ltd. The process of designing the gun began in September 1942, and an acceptable weapon was ready by January the next year. The three agencies cooperated well as they were strongly motivated to provide the Army with a useful light artillery piece as quickly as possible. During this period, the Army received thirty-eight 75mm pack howitzers, and deployed some of these guns to New Guinea.
Two artillery guns mounted on wheeled gun carriages photographed inside of a building. The weapons have a large plate mounted about half way down the length of their barrels.
The new gun used as many standard 25-pounder parts as possible, but included a number of major differences in order to reduce the weapon's weight. Modifications included shortening the gun's barrel and recuperator, making the trail lighter, and incorporating the new recoil system which had been developed to allow 25-pounders to be mounted in the Australian-designed Sentinel tank. The guns weighed 1.25 tons, had a 49.825 inches (1,266 mm) long barrel and a maximum range which was approximately 87 percent that of the standard gun. The QF 25-pounder Short could use three standard charges to obtain a range of up to 10,400 yards (9,500 m). This range could be extended to 11,500 yards (10,500 m) if a super charge was used, though standing instructions warned against doing so except in emergencies due to the strain these charges placed on the gun carriage. The gun could fire the same variety of ammunition as the standard 25-pounder; namely high explosive, armour piercing, smoke, gas, propaganda and illumination shells. While the prototype gun was fitted with a gun shield, this was later removed and not incorporated into the production weapons.
The QF 25-pounder Short incorporated a number of design features which sought to increase its mobility. The gun could be broken down into 13 or 14 parts in under two minutes, allowing it to be air dropped from aircraft or packed into Jeeps. Of these parts, only the recuperator and front trail weighted over 135 kilograms (298 lb). Assembled guns could also be towed by a Jeep, which was advantageous as it was possible to transport these vehicles inside of aircraft. The gun carriage was very different from that in the standard 25-pounder, and included a new cradle, trail and axles. The guns were initially fitted with stabilisers to reduce stress on their wheels when firing, but these were later removed as they caused problems when reversing or running up the guns in action.
Initial testing of the prototype QF 25-pounder Short was completed in early December 1942. The 2/1st Field Regiment also trialled the gun in New Guinea during early 1943. Large-scale production began in early 1943, after minor modifications were made to the design, and the Army placed an initial order for 112 guns. A second order was later placed for 100 more. This lot incorporated the Mark II carriage, which had larger wheels and tyres to prevent the problem with wheel bounce encountered by the first lot. Altogether, 213 guns were manufactured by the time production ceased in 1944. As completed, the gun's full designation was Ordnance QF 25-pounder Short (Aust) Mark I, but it was nicknamed the 'snort' by Australian soldiers.