The StG 45(M) (abbreviation of Sturmgewehr 45, "Assault Rifle 45") sometimes referred to as the MP 45(M), was a prototype
assault rifle developed by
Mauser for the ''
Wehrmacht
The ''Wehrmacht'' (, ) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the ''Heer'' (army), the '' Kriegsmarine'' (navy) and the ''Luftwaffe'' (air force). The designation "''Wehrmacht''" replaced the previo ...
'' at the end of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
, using an innovative
roller-delayed blowback operating system. It fired the
7.92×33mm Kurz (or "Pistolenpatrone 7.9mm") intermediate cartridge at a
cyclic rate
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. This can be influenced by several factors, including operator training level, mechanical limitations, ammunition availability, and weapon condition. In m ...
of around 450 rounds per minute.
Overview
![Munster Sturmgewehr 45 (dark1)](https://upload.wikimedia.org/wikipedia/commons/6/6c/Munster_Sturmgewehr_45_%28dark1%29.jpg)
The origin of this rifle can be traced back to the final years of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
when
Mauser engineers at the Light Weapon Development Group (''Abteilung 37'') at
Oberndorf am Neckar designed the MKb ''Gerät'' 06 (''Maschinenkarabiner Gerät 06'' or "machine carbine instrument 06") prototype
assault rifle chambered for the intermediate
7.92×33mm Kurz cartridge, first with the ''Gerät'' 06 model using a roller-locked mechanism which was unique for being gas operated, as opposed to recoil operation, originally adapted from the
MG 42 machine gun, but with a fixed barrel and conventional gas-actuated piston rod.
After observing bolt-bounce during firing trails of the roller locked
''Gerät 03'' prototype semi-automatic rifle Dr. Karl Maier, one of Mauser's scientists at the time, realized that with careful attention to the mechanical ratios, the gas system could be omitted.
[Senich (1987), p. 158.] The resultant weapon, the ''Gerät'' 06H (the "H" suffix is an abbreviation for ''halbverriegelt'' or "half-locked") was assigned the designation StG 45(M) (''Sturmgewehr 45(M)'').
Though appearing simple, developing the roller-delayed blowback firearm action was a hard technical and personal effort, as German engineering, mathematical and other scientists had to work together on a like-it-or-not basis led by
Ott-Helmuth von Lossnitzer, the director of Mauser Werke's Weapons Research Institute and Weapons Development Group. Experiments showed roller-delayed blowback firearms exhibited bolt-bounce. To counter bolt- bounce the perfect angle choice on the nose of the bolt head had to be found. Mathematician Dr. Karl Maier provided analysis of the components, assemblies in the development project. In December 1943 Maier came up with an equation that engineers used to change the angles in the receiver to 45° and 27° on the locking piece relative to the longitudinal axis solving the bolt-bounce problem. With these angles the geometrical transmission ratio of the boltcarrier to the bolthead became 3:1, so the rear boltcarrier was forced to move three times faster than the bolthead. The rearward forces on the boltcarrier and receiver were 2:1. The force and impulse transmitted to the receiver increases with the force and impulse transmitted to the boltcarrier. Making the boltcarrier heavier lessens the recoil velocity. For Mausers Gerät 06H/StG 45(M) project Maier assumed a 120 g bolthead and 360 g boltcarrier (1 to 3 ratio). However, the design required that the bolt started moving while the bullet was still in the barrel and the spent case fully pressurized. Using traditionally cut
chambers
Chambers may refer to:
Places
Canada:
*Chambers Township, Ontario
United States:
*Chambers County, Alabama
* Chambers, Arizona, an unincorporated community in Apache County
* Chambers, Nebraska
* Chambers, West Virginia
* Chambers Township, Hol ...
resulted in separated cartridge case heads during testing. This problem was solved by cutting 18 longitudinal gas relief flutes in the chamber. Fluting the end of the chamber allowed combustion gasses to float the neck and front of the cartridge case providing pressure equalization between the front outer surface of the cartridge case and its interior. During the process, the front cartridge case would typically show blackened, longitudinal scorch marks around the diameter of the case which was characteristic for later roller-delayed blowback-operated small arms, which also used the fluted chamber principle.
The roller-delayed blowback firearm action was patented by Mauser’s Wilhelm Stähle and
Ludwig Vorgrimler.
Like the German
FG 42 battle rifle/automatic rifle and
''Sturmgewehr'' 44 assault rifle the StG 45(M) was one of the first inline firearms incorporating a "straight-line" recoil configuration. This layout places both the
center of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...
and the position of the shoulder stock nearly in line with the longitudinal axis of the barrel bore, a feature increasing controllability by reducing
muzzle rise during burst or automatic fire.
[Senich (1987), p. 239.]
The elevated sight line over the bore axis layout was also adopted from these designs as it helps to extend the
"battle zero" range. The current trend for elevated sights and flatter shooting higher-velocity intermediate cartridges in assault rifles is in part due to a desire to further extend the maximum point-blank range, which makes such a rifle easier to use.
The StG 45(M) was intended to replace the ''Sturmgewehr'' 44 assault rifle, because the latter was rather expensive and time-consuming to produce. Compared to the StG44's cost of , the StG45(M)'s calculated cost was . Like the ''Sturmgewehr'' 44 the weapon made extensive use of (for the 1940s) advanced cost-saving
pressed and stamped steel components rather than machined parts. Partskits for only 30 complete rifles were produced before the war ended. The StG 45(M) had an elevated iron sights line over the bore axis in part to optimize the maximum
point-blank range
Point-blank range is any distance over which a certain firearm can hit a target without the need to compensate for bullet drop, and can be adjusted over a wide range of distances by sighting in the firearm. If the bullet leaves the barrel para ...
of the compared to full-power rifle cartridges modest external ballistic performance of the 7.92×33mm Kurz cartridge, ergonomics and recoil management.
While the StG45(M) was intended to use the same 30-round magazine as its predecessor, the rifle is commonly pictured with the 10-round magazine designed for the ''
Volkssturmgewehr
The Volkssturmgewehr ("People's Storm - Rifle") is the name of several rifle designs developed by Nazi Germany during the last months of World War II. They share the common characteristic of being greatly simplified as an attempt to cope with sev ...
''. The shorter magazine was used by Mauser engineers during testing, as its lower profile was easier to use when test-firing at the Mauser facility range.
Post–World War II developments
![AME1](https://upload.wikimedia.org/wikipedia/commons/2/2d/AME1.jpg)
The German technicians involved in developing the ''Sturmgewehr'' 45 continued their research in France at
CEAM. The StG45 mechanism was modified by Ludwig Vorgrimler and Theodor Löffler at the
Mulhouse
Mulhouse (; Alsatian: or , ; ; meaning '' mill house'') is a city of the Haut-Rhin department, in the Grand Est region, eastern France, close to the Swiss and German borders. It is the largest city in Haut-Rhin and second largest in Alsace a ...
facility between 1946 and 1949. Three versions were made, chambered in
.30 Carbine
The .30 Carbine (7.62×33mm) is a rimless carbine/rifle cartridge used in the M1 carbine introduced in the 1940s. It is a light rifle round designed to be fired from the M1 carbine's 18-inch (458 mm) barrel.
History
Shortly before World W ...
, 7.92×33mm Kurz as well as the
7.65×35mm cartridge developed by Cartoucherie de Valence and adopted in 1948. A 7.5×38mm cartridge using a partial aluminium bullet was abandoned in 1947. Löffler's design, designated the
Carabine Mitrailleuse Modèle'' 1950, was retained for trials among 12 different prototypes designed by CEAM,
MAC, and
MAS. Vorgrimler later went to work at
CETME
CETME () is a Spanish government design and development establishment. While being involved in many projects CETME was mostly known for its small arms research and development.
The CETME Model 58 and CETME Model L are its most notable project ...
in Spain and developed the line of
CETME automatic rifles.
Germany eventually purchased the licence for the CETME design and manufactured the
Heckler & Koch G3
The Heckler & Koch G3 (''Gewehr'' 3) is a 7.62×51mm NATO, select-fire battle rifle developed in the 1950s by the German armament manufacturer Heckler & Koch (H&K) in collaboration with the Spanish state-owned design and development agency CET ...
as well as an entire line of weapons built on the same system, one of the most famous being the
MP5
The Heckler & Koch MP5 (german: Maschinenpistole 5) is a 9x19mm Parabellum submachine gun, developed in the 1960s by a team of engineers from the German small arms manufacturer Heckler & Koch. There are over 100 variants and clones of the MP5, ...
.
A few other post–World War II weapons used the roller-delayed locking system, such as the
SIG SG 510
The Sturmgewehr 57 is a selective fire battle rifle designed by Schweizerische Industrie Gesellschaft (now SAN Swiss Arms) of Switzerland. It uses a roller-delayed blowback system similar to the H&K G3 and CETME rifles.
The AM 55 entered service ...
.
See also
*
StG 44
*
HIW VSK
The HIW VSK was a carbine of German origin developed by Hessische Industrie Werke. It was intended as a Volkssturm
The (; "people's storm") was a levée en masse national militia established by Nazi Germany during the last months of World ...
carbine
*
Wimmersperg Spz-kr
The Wimmersperg Spz ("Sp" stands for STEN-pistole, "z" for zweiteilig. English: Sten pistol, made of two parts) was a family of German assault rifles that was in the planning stage during the latter days of Nazi Germany.
Overview
The overall w ...
*
List of assault rifles
References
External links
*
*
*
{{DEFAULTSORT:Stg 45(M)
7.92×33mm Kurz assault rifles
Firearms by Hugo Schmeisser
Research and development in Nazi Germany
Roller-delayed blowback firearms
World War II assault rifles
World War II infantry weapons of Germany
Weapons and ammunition introduced in 1945