764mm

The 764mm (also unocially known as the 764mmBrenneke, though its designers name ocially never wasadded as a part of this cartridge name) is a rimless bot-tlenecked centerre cartridge developed for hunting. Asis customary in European cartridges the 7 denotes the 7mm bullet caliber and the 64 denotes the 64 mm (2.5 in)case length. The 764mm is a popular hunting cartridgein Central Europe and can, due to its 11.95 mm (0.470in) case head diameter and 84 mm (3.3 in) overall length,easily be chambered in Mauser 98 bolt action ries thatwere then standard issue in the German military.

1 HistoryAt the start of the 20th century the famous Germangun and ammunition designer Wilhelm Brenneke (18651951) was experimenting with the engineering conceptof lengthening and other dimensional changes regard-ing standard cartridge cases like the M/88 cartridge case,then used by the Germanmilitary in theirMauser Gewehr98 ries, to obtain extra muzzle velocity.In 1912 Brenneke designed the commercially at the timerather unsuccessful 864mm S cartridge (again in pro-duction since 2001). It was intended as a ballistic up-grade option for the Mauser Gewehr 98 ries that werethen standard issue in the German military. The Germanmilitary chose however to stick to their 857mm IS riecartridge avoiding rechambering their service ries for acartridge that due to its more favourable bore area to casevolume ratio ballistically would outperform the .30-06Springeld cartridge of the United States Army. Bren-nekes engineering concept to enlarge exterior cartridgecase dimensions like overall length and slightly larger casehead diameter compared to the German 857mm IS mil-itary cartridge case coupled to an increase in maximumpressure to create new for those days very powerful car-tridges was essentially sound and he persisted in the de-velopment of new cartridges along this line.In 1917 Brenneke necked down his 864mm S designof 1912 to 7mm calibre and introduced it as 764mmand achieved a major commercial success. The 764mmoered, compared to the 757mm Mauser, about 10 to12% extra muzzle velocity. This results in a atter trajec-tory and better performance at longer range. In the yearsbetween World War I and World War II the 764mmwas often regarded by German hunters as a miracle car-tridge and dozens of dierent factory loads where avail-able on the German market. It was that highly regarded

the Nazi German Wehrmacht (Army) during the 1930seven considered replacing the 857mm IS in favour forthe 764mm for their snipers. The Wehrmacht decided just like the German army in 1912 to stick to the857mm IS cartridge for their Mauser Karabiner 98k tokeep things as simple as possible in their logistical chain.Beside the 764mm rie cartridge Brenneke also de-signed a rimmed version for break action ries such asdouble ries and combination ries as well as for singleshot ries in 1917. The rimmed 765mmR variant of thecartridge was also immediately a commercial success.In countries where military service cartridges are bannedfor civil ownership (like previously France), the 764Brennecke is a successful cartridge for hunting andmarksmanship.

2 Cartridge dimensionsThe 764mm has 4.48 ml (69 grains H2O) cartridge casecapacity. A sign of the era in which the 764mm wasdeveloped are the gently sloped shoulders. The exteriorshape of the case was designed to promote reliable casefeeding and extraction in bolt-action ries, under extremeconditions.

7x64mm maximum C.I.P. cartridge dimensions. Allsizes in millimeters (mm).Americans would dene the shoulder angle at alpha/2 20.42 degrees. The common riing twist rate for this car-tridge is 220 mm (1 in 8.66 in), 4 grooves, lands = 6.98

1

2 6 EXTERNAL LINKS

mm, grooves = 7.24mm, landwidth = 3.70mm and theprimer type is large rie or large rie magnum dependingon the load.According to the ocial C.I.P. (Commission Interna-tionale Permanente pour l'Epreuve des Armes Feu Por-tatives) rulings the 764mm Mauser can handle up to415.00 MPa (60,191 psi) P piezo pressure. In C.I.P.regulated countries every rie cartridge combo has to beproofed at 125% of this maximum C.I.P. pressure to cer-tify for sale to consumers. This means that 764mmMauser chambered arms in C.I.P. regulated countries arecurrently (2014) proof tested at 519.00 MPa (75,275 psi)PE piezo pressure.[3]

The SAAMIMaximumAverage Pressure (MAP) for thiscartridge is 55,000 psi (379.21 MPa) piezo pressure.[4]

The American .280 Remington cartridge is probably theclosest ballistic twin of the 764mm. When comparedto the 764mm, the .280 Remington has a slightly lowermaximum allowed chamber pressure and as an American7 mm cartridge has a slightly smaller bore. European7mm cartridges all have 7.24 mm (0.285 in) grooves diameter. American 7mm cartridges have 7.21 mm(0.284 in) grooves .

3 Contemporary useAs noted, the 764mm is one of the favorite rie car-tridges in Central Europe and is oered as a chamberingoption in every major European hunting rie manufac-turers products palette. The versatility of the 764mmfor hunting all kinds of European game and the availabil-ity of numerous factory loads all attribute to the 764mmchambering popularity.[5] Loaded with short light bulletsit can be used on small European game like fox and geeseor medium game such as roe deer and chamois. Loadedwith long heavy bullets it can be used on big Europeangame like boar, red deer, moose and brown bear. The764mm oers very good penetrating ability due to afast twist rate that enables it to re long, heavy bulletswith a high sectional density. The 764mm rimmed sis-ter cartridge, the 765mmR, is also very popular in Cen-tral Europe for the same reasons as the 764mm. Theformer legal banning of (ex) military service cartridgeslike the .308 Winchester, 757mm Mauser, 857mm I,857mm IS and the .30-06 Springeld in countries likeFrance and Belgium also promoted acceptance and useof the 764mm and the 765mmR.

4 See also List of rie cartridges

Table of handgun and rie cartridges

7 mm caliber Brenneke 864mm S 9.364mm Brenneke

5 References[1] Barnes, Frank C. (1997) [1965]. McPherson, M.L., ed.

Cartridges of the World (8th Edition ed.). DBI Books. pp.355, 374. ISBN 0-87349-178-5.

[2] RWS 11.2 g HMK datasheet

[3] C.I.P. TDCC sheet 7 x 64

[4] ANSI/SAAMI Velocity & Pressure Data: Centerre Rie

[5] The RWSAmmunition Ballistic Data &Application Con-sultant shows several 7x64mm factory loads

C.I.P. CD-ROM edition 2003 C.I.P. decisions, texts and tables (free current C.I.P.CD-ROM version download (ZIP and RAR for-mat))

6 External links Homepage of the Brenneke Company Lutz Mllers webpage on the 7x64mm Brenneke(including images)

The 7x64 Brenneke" by Chuck Hawks 7 X 64 BRENNEKE" at Accurate Reloading 7x64 Brenneke cartridge dimensions" at StevesPages

Patronenportrt 7 x 64 - Kraftpaket oder Papier-tiger?, Wild und Hund 6/2005

C.I.P. TDCC sheet 7 x 64

37 Text and image sources, contributors, and licenses7.1 Text

764mm Source: https://en.wikipedia.org/wiki/7%C3%9764mm?oldid=662883946 Contributors: Alan Liefting, AliveFreeHappy, Bg-white, Boris Barowski, Magioladitis, Thernlund, Eastsidehastings, Gwern, Thomas.W, Francis Flinch, Koalorka, Lightmouse, PixelBot,Addbot, Xqbot, GrouchoBot, 777sms, ROG5728, EmausBot, ZroBot, Hornsignal, StraightAsADie and Anonymous: 12

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HistoryCartridge dimensionsContemporary useSee alsoReferencesExternal linksText and image sources, contributors, and licensesTextImagesContent license