The Maschinengewehr (Schwarzlose) M. 7, also known as the Schwarzlose MG, is a heavy machine gun, used as a standard issue firearm in the Austro-Hungarian Army throughout World War I. A simple and robust design, it remained in use with the Italian and Hungarian armies until the end of World War II.
History
In 1888, Archduke Karl Salvator of Austria and patented a delayed blowback machine gun, which was adopted by the Austro-Hungarian Army with a few modifications as the Škoda M1893 primarily for use in fortifications; Škoda Works later introduced a version with an improved feed system, the M1902, but only a few were built. Meanwhile, Andreas Wilhelm Schwarzlose began working on a delayed blowback machine gun design of his own—filling patents as early as 1900, and in 1907, the Austro-Hungarian Army selected Schwarzlose's design as a replacement for the Škoda machine gun. According to firearms author George M. Chinn, a blowback system was deliberately chosen as it was easier to manufacture than the Maxim and to avoid the gas operation used on Hotchkiss machine gun.
First produced in 1905 by Steyr, the Schwarzlose was issued to Austro-Hungarian infantry, cavalry, and mountain units in batteries with four guns each. Infantry units were issued M 07s with tripod mounts and transported by pack horses on a regimental level. By 1914, the Austro-Hungarian Army had a total of 2,761 machine guns in service, with each infantry regiment equipped with four machine gun sections with two Schwarzloses each — one section per battalion, at least on paper.
Cavalry units employed a team of three horses: one to carry the gun plus 500 rounds of ammunition while the rest carried 1,500 rounds of ammunition; during mobilization, two ammunition horses were added for each gun. Mountain machine gun batteries were similarly organized, with one horse carrying the Schwarzlose plus 11,000 rounds of ammunition while the ammunition horses carried 2,000 rounds each. Each machine gun was crewed by three or four soldiers with additional troops to carry extra ammunition, usually led by a non-commissioned officer.
The Austro-Hungarian Navy mounted the Schwarzlose on surface ships as anti-aircraft (AA) guns including the Erzherzog Karl and Tegetthoff-class battleships. The M 07/12 was also used by the Austro-Hungarian Aviation Troops (LFT), where it proved to be difficult to synchronize with the aircraft engines, and due to shortages of precision tools required to build enough synchronization gears once suitable designs were developed, the LFT aircraft were often fitted with improvised mountings on the field.
The Schwarzlose was simple to operate, reliable, and its rate of fire of 400 rounds per minute is superior over the Škoda; it also had the advantage of costing about half the price of a Maxim gun. Prior to 1912, the Schwarzlose was adopted by the Netherlands (1908), followed by Greece, Serbia, Romania, Bulgaria, Sweden, and the Ottoman Empire. In 1912, the improved M 07/12 with an increased rate of fire was introduced into service.
While Andreas Schwarzlose built the first prototypes in his private workshop, Steyr was the sole manufacturer until 1917. In that year, the Dutch set up their own production line at Hembrug to supply their military with Schwarzloses—production at the Hembrug Arsenal continued until 1940. Sweden also locally produced their own copies at the Carl Gustafs Stads Gevärsfaktori factory in Eskilstuna from 1917–1939. Unlicensed copies were made by the Chinese, with the Sichuan Arsenal producing a small batch for the warlord Xiong Kewu starting in 1918, while the Guangdong Arsenal also produced a small number in the early 1920s.
During World War I, the Austrians lost a large number of M 07/12s in the Eastern Front in 1914–1915 and they were forced to order a large number of Škoda M1913s to supplement it. The Imperial Russian Army made use of captured Schwarzloses alongside their own Maxims. In the Italian Front, the Austro-Hungarian Army made effective use of machine guns, repelling the numerically superior but outgunned Italian forces, and inflicting a large number of casualties during the Battles of the Isonzo.
During the interwar period, the M 07/12 was used by the successor states of Austria-Hungary including Austria, Hungary, Czechoslovakia, Poland, and Yugoslavia, and saw action in several conflicts such as the Russian Civil War, Polish–Soviet War, Greco–Turkish War, Colombia–Peru War, and the Spanish Civil War.
Italy received approximately 900 M 07/12s as war reparations from Austria-Hungary, issuing them to colonial troops in Africa, often in the anti-aircraft role. The Italians kept them in service until the end of World War II. During WWII, the Wehrmacht pressed captured Austrian, Dutch, Greek, Italian, and Yugoslav guns into service, issuing them to second-line troops for anti-partisan operations or to bolster AA batteries. During the final months of the war, the Schwarzlose was also used by the Volkssturm militia.
Design
The Schwarzlose is a toggle-delayed blowback, water-cooled machine gun. In comparison to the Maxim gun, the Model 1907 is simpler: it uses a single spring against 14 of the Maxim, 11 breech components plus 13 screws and pins while the Maxim uses 35 and 52 respectively; The M 07 is also about lighter. The bolt mechanism incorporates a device that oils cartridge cases to ease extraction. The only unusual feature about the gun is the need to open the top cover to load the ammunition belts and ensure the oil reservoir is full.
Several authors, including Chinn have stated that the improved M 07/12 was modified to fire without the need of lubricating the ammunition by incorporating a heavier bolt and a stronger spring; Firearms author Ian V. Hogg disputed this, writing that it was fitted with a larger oil reservoir and no production gun ever omitted the oiler. Other authors have stated that the oil pump was replaced with an oiled pad, instead.
The Schwarzlose Model 1905, 1907, and 1908 all have a cyclic rate of about 400 rounds/minute. In the Model 1907/12, this was increased to 580 rounds/minute by using a stronger mainspring. The Schwarzlose was robust and reliable, if used in its intended role as an infantry weapon. It met with less success when it was used in roles it had not been designed for, unlike the highly adaptable Maxim-derived machine guns.
Roles Infantry and naval weapon
For infantry use, the Schwarzlose was usually employed as a traditional, tripod mounted, heavy machine gun served by a crew of at least three soldiers, one of whom was the commander, usually an NCO, a gunner who carried the weapon, a third soldier who served as an ammunition carrier and loader and he would presumably also carry the tripod although in practice a fourth soldier might be added to the team to carry the tripod. Another less commonly seen method of deployment was the more compact 'backpack mount'. In this configuration the gun was fitted with a backwards folding bipod attached to the front of the water jacket near the muzzle. The backpack mount itself consisted of a square wooden frame with a metal socket in the center. When the gun was fully deployed the frame was laid on the ground, the gun's central mounting point that usually attached to a tripod now had a small mounting pin attached to it instead which was inserted into the mounting socket in the center of the wooden backpack frame and finally the bipod was folded forward. The Schwarzlose would also have seen service as a fortress weapon in which case it would have been deployed on a variety of heavy and specialized fixed mountings and it also saw some use as a naval weapon aboard ships. During World War I, the Schwarzlose was also pressed into service as an anti-aircraft gun, and, as such, it was deployed using a variety of (often improvised) mountings.
Fortification weapon
After World War I the Schwarzlose equipped the armed forces of Czechoslovakia, where it was adapted (vz. 7/24) and manufactured (vz. 24) as the těžký kulomet vz. 7/24 (heavy machine gun model 7/24) by the Janeček factory (adapted from 8 mm calibre to standard Czechoslovak munition 7,92 Mauser). When Czechoslovakia started building fortifications against Nazi Germany in 1935-1938, light fortifications, known as types 36 and 37, were partially armed with the Schwarzlose vz. 7/24.
Aircraft gun Apart from its use as a heavy infantry machine gun and as an anti-aircraft weapon, the Schwarzlose saw service with the Austro-Hungarian Luftfahrtruppe during World War I as an aircraft machine gun, a role for which it was not entirely suited. The Schwarzlose was used both as a fixed forward firing gun and as a flexible, ring mounted, defensive weapon.
Synchronizing the Schwarzlose for use in fighters turned out to be a difficult engineering challenge. A critical factor in synchronization is the time delay between the trigger movement and the moment when the bullet leaves the barrel, as during this delay the propeller will continue to rotate, moving over an angle that also varies with engine rpm. Because of the relatively long delay time of the Schwarzlose M7/12, the synchronization systems that were developed could be operated safely only in a narrow band of engine rpm. Therefore, the Austro-Hungarian fighters were equipped with large and prominent tachometers in the cockpit. The M16 version of the gun could be synchronized with greater accuracy, but a widened engine rpm restriction still had to be respected, except for aircraft equipped with Daimler synchronization gear. The result was never entirely satisfactory and Austro-Hungarian aircraft thus armed usually carried the Kravics indicator to warn the pilot of a malfunction in the synchronization gear. The Kravics propeller hit indicator consisted of electric wiring wrapped around the critical area of the propeller blades, connected to a light in the cockpit by a slip ring on the propeller shaft. If the light went out, the pilot knew the propeller had been hit.