| 7.92×57mm Mauser | ||
|---|---|---|
From left to right 9.3×62 mm, .30-06 Springfield, 7.92×57mm IS, 6.5×55mm and 7.62×51mm NATO cartridges |
||
| Type | Rifle | |
| Place of origin | Germany | |
| Service history | ||
| In service | I-variant 1888–1905 IS-variant 1905–present |
|
| Used by | Germany, United Kingdom, Spain, Czechoslovakia, Poland, Dominican Republic, Yugoslavia, The Ottoman Empire, Turkey, Iran, China, and other middle eastern countries | |
| Wars | World War I, World War II and others | |
| Production history | ||
| Designer | German Rifle Testing Commission | |
| Designed | 1888 | |
| Variants | 7.92×57mm IR and 7.92×57mm IRS (rimmed) | |
| Specifications | ||
| Case type | Rimless, bottleneck | |
| Bullet diameter | 8.08 mm / .318 (I and IR) and 8.20 / .323" (IS and IRS) | |
| Neck diameter | 9.08 mm (0.357 in) | |
| Shoulder diameter | 10.95 mm (0.431 in) | |
| Base diameter | 11.94 mm (0.470 in) | |
| Rim diameter | 11.95 mm (0.470 in) | |
| Rim thickness | 1.30 mm (0.051 in) | |
| Case length | 57.00 mm (2.244 in) | |
| Overall length | 82.00 mm (3.228 in) | |
| Case capacity | 4.09 cm³ (63 gr H2O) | |
| Rifling twist | 240 mm (1 in 9.45 in) | |
| Primer type | Large rifle | |
| Maximum pressure | 390 MPa (57,000 psi) | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 11.7 g (181 gr) RWS DK | 820 m/s (2,700 ft/s) | 3,934 J (2,902 ft·lbf) |
| 12.1 g (187 gr) RWS HMK | 820 m/s (2,700 ft/s) | 4,068 J (3,000 ft·lbf) |
| 12.7 g (196 gr) RWS TMR | 800 m/s (2,600 ft/s) | 4,064 J (2,997 ft·lbf) |
| 12.8 g (198 gr) RWS ID Classic | 800 m/s (2,600 ft/s) | 4,096 J (3,021 ft·lbf) |
| Test barrel length: 600 mm (23.62 in) Source(s): RWS / RUAG Ammotech [1] |
||
The 7.92×57mm Mauser (sometimes called the 8mm Mauser or 8x57mm IS) is a rimless bottlenecked rifle cartridge. The 7.92×57mm cartridge was adopted by the German Empire in 1905, and was the German service cartridge in both World Wars. IS stands for Infanterie, Spitz(geschoß) or "Infantry, Pointed (projectile)".
The cartridge on which it was based was adopted by Germany in 1888 as the M/88 7.92×57mm I (I stands for Infanterie or "Infantry") along with the Gewehr 1888 service rifle. It was designed by the German Gewehr-Prüfungskommission (G.P.K.) ("Rifle Testing Commission") for the Gewehr 1888 and later used in Mauser bolt-action rifles, machine guns, and other ordnance weapons.
The 1888 pattern of the M/88 cartridge is currently known in Europe as the 7.92×57mm I (C.I.P. designation). The 1905 pattern cartridge is currently known in Europe as the 8×57 IS (C.I.P. designation) and in the United States of America as the 8mm Mauser, also known as 8×57mm (SAAMI designations).[2] The widespread use in German military Gewehr 98 and Karabiner 98k service rifles designed and manufactured by Mauser caused the "Mauser" tag, though Mauser had nothing to do with the development of this cartridge. Some sources list it also as "7.92×57mm JS", as capital letters I and J were interchangeable in abbreviations at this time.
In some English-speaking areas, the cartridge is called 8mm Mauser. The British and Commonwealth forces used the 7.92×57mm Mauser cartridge in the BESA machine gun mounted on their armoured vehicles during World War II and referred to this ammunition as "7.92".
Contents |
The government-developed 7.92×57mm IS cartridge was a development of the M/88 7.92×57mm I. The older cartridge used a round-nosed bullet and was developed to be top-loaded into the magazine of the Gewehr 1888 rifle via an en bloc clip. The M/88 7.92×57mm I replaced the 11×60mm Mauser cartridge in German military service and marked Germany's switch from black powder to smokeless powder ammuntion. The new 7.92×57mm IS bullet was lighter, pointed, and 8.2 mm (0.323 in) in diameter instead of 8.08 mm (0.318 in). With the improved ballistic coefficient, the new IS cartridge had a flatter trajectory,[3] and was therefore less critical of range estimation. It was used in rifles—like the Gewehr 98, Karabiner 98k, Gewehr 41, FG 42, or Gewehr 43—and in machine guns—like the MG 08, MG 34, or MG 42.
The rimless cartridge cases have been used as parent cases for several other necked down and necked up cartridges.
The rimmed variants, the 7.92×57mm IR and the 7.92×57mm IRS, were developed later for break-barrel rifles and combination guns.[4]
Due to the cartridge's high performance and versatility it was adopted by the armed forces of various governments, including Spain, Poland, Czechoslovakia, Iran, Israel, Turkey, China, Egypt, former German African colonies, and the early Bundeswehr of West Germany. Its military use continues today in the former Yugoslavia in weapons like the Zastava M76 sniper rifle and the license-built copy of the MG 42, the SARAC M53 machine gun.[5]
During World War II it was one of the few cartridges used by both the Axis and Allied powers, a distinction it shared with the 9×19mm Parabellum pistol round. Apart from being the standard rifle cartridge of the German armed forces, it was also used by the armed forces of Great Britain in the Besa machine gun, which was mounted in some of their tanks and other armoured vehicles—it was known as "Cartridge, SA, 7.92".[6]
The 7.92×57mm IS and 7.92×57mm IRS are common chambering offerings in rifles marketed for European sportsmen, alongside broadly similar cartridges such as the 5.6×57mm, 6.5×55mm, 6.5×57mm, and the 6.5×68mm and 8×68mm S magnum hunting cartridges. Major European manufacturers like Blaser, Česká Zbrojovka firearms, Heym, Mauser Jagdwaffen GmbH and Steyr Mannlicher produce factory new 7.92×57mm IS hunting rifles and European ammunition manufacturers like Blaser, RUAG Ammotec/RWS, Sako and Sellier & Bellot produce factory new ammunition.[7] In 2004 Remington Arms offered a limited-edition Model 700 Classic bolt action hunting rifle chambered for the 7.92×57mm IS.[8] The 7.92×57mm Mauser cartridge's performance is superior to the American .30-06 Springfield cartridge and makes it suited for the hunting all large European game such as deer, chamois, mouflon, wild Boar and bears.[9]
However, it cannot be used in countries which ban civil use of former or current military rifle cartridges, like France.
Beside the 7.92x57mm Mauser and 7.92×57mm IS rimless rifle cartridges rimmed versions for break-action rifles also exist. The rimmed 7.92×57mm IR and 7.92×57mm IRS variants are offered as a chambering option in European break-action rifles.[4][10]
The mainly European arms standards body Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives ("Permanent International Commission for portable firearms testing")—an organisation for standards in ammunition for civilian use—currently designates two 7.92mm cartridges of 57mm case length. Following the original military nomenclature C.I.P. assigned the 7.92×57 I and 7.92×57 IS civil nomenclature to these cartridges.[11]
The United States standardizing body for sporting cartridges Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) designates the 7.92×57mm Mauser cartridge as the 8mm Mauser, also known as 8×57mm.[2]
The SAAMI (voluntary) pressure limitation for the 7.92×57mm Mauser cartridge is Piezo SAAMI Pmax = 241.317 MPa (35,000 psi) or 37,500 CUP.[12] This is considerably lower than the C.I.P. pressure limit and is done for liability reasons, in case the 7.92×57mm IS cartridge is fired in an 'I' bore rifle that has a narrower throat and barrel diameter, to avoid catastrophic firearm failures that could endanger users or bystanders. European ammunition manufacturers generally only load to the lower pressure limit for "I" bore cartridges; and the US based manufacturer Hornady followed their lead in their (now discontinued) EuroSpec brand 8×57 JS load.
Sometimes, the cartridge is called 8x57mm, however, this seems to be a persevering misnomer by English speaking sources. This designation was not used in Germany and is not used by either the C.I.P. or the SAAMI.[2] The British Besa machine gun used in armored vehicles during World War II was chambered for the 7.92x57mm Mauser and the British referred to this ammunition as 7.92mm. US intelligence documents from World War II also refers to the cartridge as 7.92mm.[13][14]
The letter "J" often mentioned by English speaking sources is actually an "I" for Infanterie (German for "infantry"). A stamped "I" at the cartridge bottom in writing styles used in the past in Germany could be easily mistaken for a "J". Even in the 21st century the "I" is often substituted by a "J" in English speaking communities and German ammunition manufacturers often write "JS" instead of "IS" to avoid confusing customers. The letter "S" stands for Spitzgeschoß ("pointed bullet"), and the English word "spitzer" for that style of bullet is derived from this German term.
The 7.92×57mm I cartridge has 4.03 ml (62 grains) H2O cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions.
7.92×57mm I maximum C.I.P. cartridge dimensions. All sizes in millimeters.
Americans would define the shoulder angle at alpha/2 ≈ 19.1 degrees. The common rifling twist rate for this cartridge is 240 mm (1 in 9.45 in), 4 grooves, Ø lands = 7.80 mm, Ø grooves = 8.07 mm, land width = 4.40 mm and the primer type is large rifle.
According to the official C.I.P. guidelines the 7.92×57mm I case can handle up to 380 MPa (55114 psi) piezo pressure. In C.I.P. regulated countries every rifle and cartridge combination has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.
The 7.92×57mm IS cartridge has a cartridge case capacity of 4.09 ml (63 grains) H2O. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions.
7.92×57mm Mauser maximum C.I.P. cartridge dimensions. All sizes in millimeters.
Americans would define the shoulder angle at alpha/2 ≈ 19.1 degrees. The common rifling twist rate for this cartridge is 240 mm (1 in 9.45 in), 4 grooves, Ø of the lands = 7.89 mm, Ø grooves = 8.20 mm, land width = 4.40 mm and the primer type is large rifle.
According to the official C.I.P. guidelines the 7.92×57mm Mauser case can handle up to 390 MPa (56,564 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combination has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.
In 7.92×57mm caliber, "there were many German military versions of the cartridge, and Germany never stopped its development of different variations until the end" of World War II. "The bullet lengths varied a great deal through the different types, but all were loaded to an overall length" of 80.5 mm (3.17 in). The Germans had started using steel cases in World War I, "and by the end of 1943, most German ammunition had that type of case."[15] The weights and case capacities of the Word War II military cartridge cases varied somewhat. The German military ammunition manufacturer Polte produced brass cartridge cases weighing 10.32 g (159 gr) with 4.03 ml (62 gr) H2O case capacity and steel cartridge cases weighing 10.90 g (168 gr) with 3.95 ml (61 gr)H2O case capacity.[16]
| Name | Year | Caliber | Bullet weight | Length | Rim | Base | Shoulder | Neck | OAL | Muzzle velocity | Muzzle energy |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7.92×57mm I | 1888 | 8.07 millimetres (0.318 in) | 14.6 g (226 gr) | 57 millimetres (2.2 in) | 11.95 millimetres (0.470 in) | 11.94 millimetres (0.470 in) | 10.95 millimetres (0.431 in) | 8.99 millimetres (0.354 in) | 80.5 millimetres (3.17 in) | 639 metres per second (2,100 ft/s) | 2,983 joules (2,200 ft·lbf) |
| 7.92×57mm IS | 1905 | 8.2 millimetres (0.32 in) | 9.9 g (154 gr) | 57 millimetres (2.2 in) | 11.95 millimetres (0.470 in) | 11.94 millimetres (0.470 in) | 10.95 millimetres (0.431 in) | 9.08 millimetres (0.357 in) | 80.5 millimetres (3.17 in) | 878 metres per second (2,880 ft/s) | 3,857 joules (2,845 ft·lbf) |
| 7.92×57mm IS | 1934 | 8.2 millimetres (0.32 in) | 12.8 g (197 gr) | 57 millimetres (2.2 in) | 11.95 millimetres (0.470 in) | 11.94 millimetres (0.470 in) | 10.95 millimetres (0.431 in) | 9.08 millimetres (0.357 in) | 80.5 millimetres (3.17 in) | 760 metres per second (2,500 ft/s) | 3,697 joules (2,727 ft·lbf) |
The German standard sS (schweres Spitzgeschoß—"heavy pointed bullet") ball bullet was 35.3 mm (1.39 in) long, boat-tailed, and very well made.[15] It was lead filled, had a gilding-metal-plated jacket, and weighed 12.8 grams (198 gr). It offered the best aerodynamic efficiency and external ballistic performance of any standard rifle bullet used during World War II, with a G1 ballistic coefficient between 0.593 and 0.557 (ballistic coefficients are somewhat debatable). When fired at the typical muzzle velocity of 760 m/s (2,493 ft/s) out of a 600 mm (23.6 in) barrel the sS bullet retained supersonic velocity up to and past 1,000 m (1,094 yd) (V1000 ≈ Mach 1.07) under International Standard Atmosphere conditions at sea level (air density ρ = 1.225 kg/m3). Even by contemporary (2010) standards 1000+ m (1,094+ yards) effective range is quite remarkable for a standard military rifle round.[nb 1] For recognition the circular groove between cap and brass was green, and it had a yellow colored bullet.
During World War II German snipers were issued with purpose manufactured sniping ammunition, known as the 'effect-firing' sS round.[18] The 'effect-firing' sS round featured an extra carefully measured propellant charge and seated a sS full metal jacketed boat tail projectile of match grade build quality, lacking usual features such as a seating ring or cannelure to further improve the already high ballistic coefficient.[19]
Special ammunition included:[16][20][21]
German tracer bullets "were the best put out by any country — streamlined and with excellent ballistics".[15]
British cartridges included "Ball", "Armour-Piercing", "Tracer", and "Incendiary". Blanks and a Drill round were also available for instruction purposes. The Drill round was an aluminium bullet fixed in a chromium-plated case which had three deep lengthwise recesses painted red to identify it. Ammunition was supplied in belted form with 225 rounds per belt.[6]
| Designation | Marks | Annulus colour | Notes |
|---|---|---|---|
| Cartridge, SA, Ball, 7.92mm | Mark I.Z, Mark II.Z | dark purple if present | Mark II.Z bullet has "flatter" nose and longer parallel portion to engage with rifling |
| Cartridge, SA, Armour-piercing, 7.92mm | Mark I.Z, Mark II.Z | Green | hard steel core, lead-antimony sleeve, steel envelope |
| Cartridge, SA, Tracer, 7.92mm | Mark I.Z, Mark II.Z | Red | red tracer composition in unstreamlined bullet. Effective for 900 yards. |
| Cartridge, SA, Incendiary, 7.92mm | Mark I | Blue |
The Ball case was filled with a charge of around 45 grains of nitro-cellulose.[6]
The British cartridge was used in only one weapon—the "7.92mm BESA machine gun". This was a Czech design adopted shortly before the war as a move towards rimless ammunition across the armed service. However the move was disrupted by the lead up to war. The BESA was only fitted to tanks and armoured cars of British design (the original Czech design was also produced for German use following the occupation of Czechoslovakia) and captured German ammunition was used when available.
Maximum muzzle velocity comparison in % of the probably most proliferated European and American 8 mm rifle cartridges out of 650 mm (25.59 in) long barrels loaded with relatively light to heavy 8 mm bullets to their C.I.P. or SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute) sanctioned maximum pressures.
| Bullet weight gram (grain) | 8.23 g (127 gr) | 9.72 g (150 gr) | 11.34 g (175 gr) | 12.96 g (200 gr) | 14.26 g (220 gr) | Case capacity (%) |
| 7.92×57mm IS | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| 7.92×64mm S | 102.7 | 102.7 | 102.8 | 102.9 | 102.9 | 110.3 |
| .325 WSM | 108.7 | 109.1 | 109.0 | 109.3 | 111.1 | 131.7 |
| 7.92×68mm S | 108.4 | 108.5 | 108.7 | 110.5 | 112.3 | 136.5 |
| 8mm Rem. Mag. | 111.9 | 112.3 | 114.5 | 115.3 | 116.0 | 157.1 |
This comparison is not totally objective since the 8mm Remington Magnum and .325 WSM operate at 448.16 MPa (65000 psi), the 7.92×68mm S at 440 MPa (63817 psi), the 7.92×64mm S at 405 MPa (58740 psi) and the 7.92×57mm Mauser at 390 MPa (56564 psi) maximum chamber pressure. Higher chamber pressure results in higher muzzle velocities.
This was the parent case for many other later cartridges, such as:
