8 mm Remington Magnum
Encyclopedia
The 8mm Remington Magnum belted
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...

 rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

 cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

 was introduced by Remington Arms Company in 1978 as a new chambering for the model 700
Remington 700
The Model 700 series of firearms are bolt-action rifles manufactured by Remington Arms since 1962. All are based on the same centerfire bolt action. They often come with a 3, 4 or 5-round internal magazine depending on caliber, some of which have a floor-plate for quick-unloading, and some of which...

 BDL rifle. The 8 mm Remington Magnum's parent case is the .375 H&H Magnum
.375 H&H Magnum
The .375 Holland & Holland Magnum is a powerful rifle round and one of the best-known and most popular medium-bore cartridges in the world. The .375 H&H was only the second cartridge ever to feature a belt, now common among magnum rounds. A popular misconception is that the belt is for headspace,...

. It is a very long and powerful cartridge that cannot be used in standard length actions, such as those that accommodate the .30-06 Springfield
.30-06 Springfield
The .30-06 Springfield cartridge or 7.62×63mm in metric notation, was introduced to the United States Army in 1906 and standardized, and was in use until the 1960s and early 1970s. It replaced the .30-03, 6 mm Lee Navy, and .30 US Army...

.

Background

The 8 mm Remington Magnum was intended to compete with the .300 Weatherby Magnum
.300 Weatherby Magnum
The .300 Weatherby Magnum is a .30 caliber rifle cartridge created by Roy Weatherby in 1944 and produced by Weatherby. It has become the most popular of all the Weatherby cartridges.-Background:...

 and .338 Winchester Magnum
.338 Winchester Magnum
The .338 Winchester Magnum is a .33 caliber belted rimless bottlenecked cartridge introduced in 1958 by Winchester Repeating Arms Company|Winchester. It is based on the blown out, shortened .375 H&H Magnum. The .33 is the caliber at which medium bore cartridges are considered to begin...

. Remington’s decision to use a metric bullet may have been prompted by their past success with the 7 mm bore diameter.

Even though the 8 mm Remington Magnum has never been very popular, it is a very suitable cartridge for the hunting of elk, moose, caribou, and larger African antelope. However, the .338 Winchester Magnum had a 30 year head start
Head start (positioning)
In positioning, a head start is a start in advance of the starting position of others in competition, or simply toward the finish line or desired outcome...

 on the market, and is short enough for medium length actions, which increases the models of rifles it could be produced in. It is also available with heavier bullets, although this isn't a problem for people that load their own rounds of this caliber. Bullet selection is quite critical with the 8mm Remington Magnum since the bullets have to be designed and constructed to hold together at magnum velocities.

Cartridge dimensions

The 8mm Remington Magnum has 6.43 ml
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...

 (99 grain
Grain (measure)
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...

) H2O cartridge case capacity.



8mm Remington Magnum maximum C.I.P. cartridge dimensions. All sizes in millimetres (mm).

Americans would define the shoulder angle at alpha/2 = 25 degrees. The common rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

 twist rate for this cartridge is 254 mm (1 in 10 in), 6 grooves, Ø lands = 8.00 mm, Ø grooves = 8.20 mm, land width = 3.10 mm and the primer type
Percussion cap
The percussion cap, introduced around 1830, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather.Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the...

 is large rifle magnum.

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives is an international organisation whose members are 14 states, mainly European....

) guidelines the 8mm Remington Magnum case can handle up to 460 MPa (66717 psi) piezo pressure. This is a very high maximum chamber pressure limit for a rifle cartridge and ≈ 2.6 % above the SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...

 maximum piezo pressure rating of 448 MPa (65000 psi). In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

The German 8 x 68 S cartridge introduced in 1939 is probably the closest ballistic twin of the 8 mm Remington Magnum. The 8 x 68 S is however a rebated rim
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...

 cartridge.

The 8mm Remington Magnum in field use

The 8 mm Remington Magnum as a pure civil cartridge can be used in countries which ban civil use of former or current military ammunition.

A powerful cartridge like the 8 mm Remington Magnum has its drawbacks. Like every other big game cartridge it presents a stout recoil. Since there are not many factory loads available, the 8 mm Remington Magnum is often used by reload
Reload
Reload may refer to:* Repeated handloading of firearm cartridges, adding powder and primer to an empty metallic shell casing to create ammunition* Reloading scam...

ers. They can use this cartridge to create powerful loads by handloading
Handloading
Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components , rather than purchasing completely assembled, factory-loaded cartridges...

, while staying within the 448 MPa (65000 psi) SAAMI piezo pressure limit. Combined with bullets with jackets designed for magnum cartridge muzzle velocities, and barrels of 650 mm (25.6 in) or longer to promote high muzzle velocities, the 8 mm Remington Magnum offers the flattest trajectory and best long range performance of the commercially available 8 mm rifle cartridges.

From 8 mm caliber upwards the rise of sectional density
Sectional density
Sectional density is the ratio of an object's mass to its cross-sectional area. It conveys how well an object's mass is distributed to overcome resistance. For illustration, a needle can penetrate a target medium with less force than a coin of the same mass...

 and penetrating capability of practical spin stabilized rifle bullets (bullets up to 5 to 5.5 calibers in length) tends to flatten out.

This means that loaded with light, short and soft nosed 8 mm bullets the 8 mm Remington Magnum can be used on remarkably small game. Loaded with heavy, long and hard (solid copper) bullets the 8 mm Remington Magnum offers enough velocity derived power to penetrate heavy and dangerous game. With developed handloads, the 8mm Remington Magnum is capable of driving a 220 grain boat tail bullet in excess of 3,000 ft/sec, and delivers as much energy at 500 yards (457m) as the .308 Winchester
.308 Winchester
The .308 Winchester is a rifle cartridge and is the commercial cartridge upon which the military 7.62x51mm NATO centerfire cartridge is based. The .308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62x51mm NATO T65...

 has at the muzzle. Lighter bullets of 150-180 grains can be driven to velocities of 3,300-3,500 ft/sec, putting it in the same class as the larger cased .300 Remington Ultra Magnum
.300 Remington Ultra Magnum
The .300 Remington Ultra Magnum, also known as the .300 Ultra Mag or .300 RUM is a 7.62 mm caliber rifle cartridge , 7.62x72mm, or .30 caliber rifle cartridge introduced by Remington Arms in 1999. The .300 Remington Ultra Magnum is one of the largest commercially available .30 caliber magnums...

; Such loads offer a very flat trajectory, making it an optimal choice for deer and elk sized game at very long range. The 8 mm Remington Magnum is suitable for hunting almost any game animal on the planet, though certain sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

 countries have a 9.53 mm (.375 in) or 10.2 mm (.40 in) minimum caliber rule for hunting Big Five game
Big Five game
The phrase Big Five game was coined by white hunters and refers to the five most difficult animals in Africa to hunt on foot. The term is still used in most tourist and wildlife guides that discuss African wildlife safaris. The collection consists of the lion, African elephant, cape buffalo,...

 - i.e. leopard
Leopard
The leopard , Panthera pardus, is a member of the Felidae family and the smallest of the four "big cats" in the genus Panthera, the other three being the tiger, lion, and jaguar. The leopard was once distributed across eastern and southern Asia and Africa, from Siberia to South Africa, but its...

, lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...

, cape buffalo, rhinoceros
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....

 and African elephant. In the Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...

, where there are no ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...

 limits for hunting Big Five game
Big Five game
The phrase Big Five game was coined by white hunters and refers to the five most difficult animals in Africa to hunt on foot. The term is still used in most tourist and wildlife guides that discuss African wildlife safaris. The collection consists of the lion, African elephant, cape buffalo,...

, the 8 mm Remington Magnum’s somewhat smaller sister cartridge the 8 x 68 S is used successfully for hunting African elephant. At equal chamber pressure and 650 mm (25.6 in) barrel length the larger 8 mm Remington Magnum produces 3 to 5 % extra muzzle velocity.

8mm cartridges compared

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
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...

 (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 x 57 Mauser (8 x 57 IS) 100.0 100.0 100.0 100.0 100.0 100.0
8 x 64 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
8 x 68 S 108.4 108.5 108.7 110.5 112.3 136.5
8 mm Rem. Mag. 111.9 112.3 114.5 115.3 116.0 157.1


This comparison is not totally objective since the 8 mm Remington Magnum and .325 WSM
.325 WSM
.325 Winchester Short Magnum is an 8 mm caliber rebated rim bottlenecked centerfire short magnum cartridge that was introduced in 2005 by Winchester...

 operate at 448.16 MPa (65000 psi), the 8 x 68 S at 440 MPa (63817 psi), the 8 x 64 S at 405 MPa (58740 psi) and the 7.92 x 57 mm Mauser at 390 MPa (56564 psi) maximum chamber pressure. Higher chamber pressure results in higher muzzle velocities.

7mm STW (Shooting Times Westerner)

The 8 mm Remington Magnum case has functioned as the parent case for the 7mm STW, which is essentially a 7mm (.284 caliber) necked-down version of the 8 mm Remington Magnum. Designed by Layne Simpson, Editor of Shooting Times magazine, the wildcat status of the 7mm STW ended in 1996 when it got SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...

 certified and became an officially registered and sanctioned member of the 8 mm Remington Magnum "family" of magnum rifle cartridges. With top handloads pushing a 150 grain bullet at nearly 3,400 feet per second, it is one of the fastest mid-bore rifle cartridges extant and is noted for its extremely flat trajectory. It is outclassed only by the Lazzeroni 7.21 Firebird and Remington's 7mm RUM

.416 Remington Magnum

The 8 mm Remington Magnum case also has functioned as the parent case for the .416 Remington Magnum
.416 Remington Magnum
The .416 Remington Magnum is a .416 caliber of a belted bottle-necked design. The cartridge was intended as a dangerous game hunting cartridge and released to the public in 1989. The cartridge uses the case of the 8 mm Remington Magnum as a parent cartridge. When the cartridge was released in...

, which is a .416" caliber necked up version of the 8 mm Remington Magnum. Unlike the 7 mm STW, the .416 Remington Magnum never had a wildcat status. It was designed by Remington and released directly to the public in 1988.

Wildcats

Cartridges that are not officially registered with nor sanctioned by C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives is an international organisation whose members are 14 states, mainly European....

) or its American equivalent, SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...

 (Sporting Arms and Ammunition Manufacturers’ Institute) are generally known as wildcats
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...

. By blowing out standard factory cases the wildcatter generally hopes to gain extra muzzle velocity by increasing the case capacity of the factory parent cartridge case by a few percent. Practically there can be some muzzle velocity gained by this method, but the measured results between parent cartridges and their 'improved' wildcat offspring is often marginal. Besides changing the shape and internal volume of the parent cartridge case, wildcatters also can change the original caliber. A reason to change the original caliber can be to comply with a minimal permitted caliber or bullet weight for the legal hunting of certain species of game.

Wildcats are not governed by C.I.P. or SAAMI rules so wildcatters can capitalize the achievable high operating pressures. Because the 8 mm Remington Magnum offers an exceptional sturdy, pressure resistant cartridge case that can relatively easily be reloaded with primers, powder and bullets and hence be reused several times it has become quite popular amongst wildcatters. With the 8 mm Remington Magnum as the parent case wildcatters have created 6.35 mm (0.257 in) (.257 STW), 6.5 mm (0.264 in) (6.5 mm STW), .30 caliber (.30–8 mm Remington Magnum, .300 Jarrett), 8 mm caliber (8 mm Jarrett), .338 caliber (.338 Jarrett), 0.358 in caliber (.358 STA) and 9.53 mm (0.375 in) (.375 JRS [John R. Sundra]) variants.

.358 STA (Shooting Times Alaskan)

Another brainchild of Layne Simpson, the .358 STA is an 8 mm Remington Magnum case necked up to accept .358 Caliber bullets with no other changes. Able to propel a 300 grain bullet at over 2700 feet per second for 4,900 ft./lbs. of energy, the .358 STA is a formidable big game cartridge. It has never emerged as a production cartridge and has had very limited success as a wildcat, overshadowed by the more popular .375 caliber commercial and custom cartridges.
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