.284 Winchester
Encyclopedia
The .284 Winchester is an example of a commercially rather unsuccessful cartridge that has enjoyed a resurgence in interest due to interest from long-range competitive shooters . Introduced by Winchester in 1963, the .284 Winchester was designed to squeeze .270 Winchester
and .280 Remington
performance from the new Model 100 autoloader and Model 88 lever action rifles.
The end result was a 7 mm cartridge
with about the same overall length as the .308 Winchester
but with a wider body that yields a powder capacity about the same as that of the .270 Winchester and .280 Remington.
was available in .284 Winchester, and Ruger produced a small run of Ruger Model 77 rifles in this caliber. Surprisingly enough, Ultra Light Arms now builds more Model 20 rifles in .284 Winchester than all other calibers combined.
(66 grains
H2O) cartridge case capacity. The case has a rebated rim and a body almost as large in diameter as that of typical belted magnum cases.
.284 Winchester maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2 = 35 degrees. The common rifling
twist rate for this cartridge is 254 mm (1 in 10 in), 6 grooves, Ø lands = 7.00 mm, Ø grooves = 7.19 mm, land width = 2.79 mm and the primer type
is large rifle.
According to the official C.I.P. (Commission Internationale Permanente Pour L'Epreuve Des Armes A Feu Portative) guidelines the .284 Winchester case can handle up to 440 MPa (63,816 psi) piezo pressure. 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 SAAMI
pressure limit for the .284 Winchester is set at 56,000 PSI
, piezo pressure.
When the cartridge over all length is maintained, deeper-seating is necessary with heavier bullets. This reduces usable powder capacity and hence performance compared to longer cartridges like the 280 Remington.
The American .280 Remington
cartridge is probably the closest ballistic twin of the .284 Winchester. When compared to the .284 Winchester the .280 Remington has a slightly different maximum allowed chamber pressure and case capacity.
These ballistics make it clear that the .284 Winchester is as good as the .280 Remington with the same weight bullet. Of course the short, handy mountain rifles for which the .284 Winchester seems best suited seldom come with 24 in barrels. Aside from Winchester, no other major company has ever loaded factory ammunition for the .284 Winchester.
The cartridge is sometimes used for long range target shooting like F-Class and 1000 yd/m long range competitions, where participants usually handload their ammunition
. For this application the .284 Winchester is loaded with 175 and 180 gr very-low-drag bullets (vld).
The .284 Winchester is not popular in Europe, where it competes with the 7x64mm
, to which it is almost ballistically identical. When compared to the .284 Winchester the 7×64mm has a lower C.I.P. maximum allowed chamber pressure and as a European 7 mm cartridge has a slightly larger bore. European 7 mm cartridges all have 7.24 mm (0.285 in) grooves Ø diameter. American 7 mm cartridges have 7.21 mm (0.284 in) grooves Ø.
.
Today, the most popular and useful .284 Winchester-case based cartridge is not the original, but rather the 6.5-284 Norma. This former wildcat was developed for long range target shooting where participants usually handload their ammunition
. It is currently one of the most used non-wildcat cartridges by match shooters in F-Class and 1000 yd/m benchrest long range competitions.
.270 Winchester
The .270 Winchester was developed by Winchester Repeating Arms Company in 1923 and unveiled in 1925 as a chambering for their bolt-action Model 54. The cartridge is based upon the .30-06 Springfield...
and .280 Remington
.280 Remington
The .280 Remington, also known as the 7 mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721 and 725 rifles. The .280 is based on the .30-06 Springfield necked down to accept 7 mm bullets, with the neck moved forward .050in...
performance from the new Model 100 autoloader and Model 88 lever action rifles.
The end result was a 7 mm cartridge
7 mm caliber
This article lists firearm cartridges which have a bullet in the to caliber range.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge....
with about the same overall length 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...
but with a wider body that yields a powder capacity about the same as that of the .270 Winchester and .280 Remington.
History
At one time the Savage Model 99Savage Model 99
The Model 99, and its predecessor models 1895 and 1899, are a series of lever action rifles created by the Savage Arms Company in Utica, New York.-History:...
was available in .284 Winchester, and Ruger produced a small run of Ruger Model 77 rifles in this caliber. Surprisingly enough, Ultra Light Arms now builds more Model 20 rifles in .284 Winchester than all other calibers combined.
Cartridge dimensions
The .284 Winchester has 4.29 mlLitre
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...
(66 grains
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. The case has a rebated rim and a body almost as large in diameter as that of typical belted magnum cases.
.284 Winchester maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2 = 35 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 = 7.00 mm, Ø grooves = 7.19 mm, land width = 2.79 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.
According to the official C.I.P. (Commission Internationale Permanente Pour L'Epreuve Des Armes A Feu Portative) guidelines the .284 Winchester case can handle up to 440 MPa (63,816 psi) piezo pressure. 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 SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...
pressure limit for the .284 Winchester is set at 56,000 PSI
Pounds per square inch
The pound per square inch or, more accurately, pound-force per square inch is a unit of pressure or of stress based on avoirdupois units...
, piezo pressure.
When the cartridge over all length is maintained, deeper-seating is necessary with heavier bullets. This reduces usable powder capacity and hence performance compared to longer cartridges like the 280 Remington.
The American .280 Remington
.280 Remington
The .280 Remington, also known as the 7 mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721 and 725 rifles. The .280 is based on the .30-06 Springfield necked down to accept 7 mm bullets, with the neck moved forward .050in...
cartridge is probably the closest ballistic twin of the .284 Winchester. When compared to the .284 Winchester the .280 Remington has a slightly different maximum allowed chamber pressure and case capacity.
Contemporary use
For open country hunting of deer and pronghorn, the .284 Winchester loaded with the Speer 130 gr spitzer at 3100 ft/s (944.9 m/s) will do anything the .270 Winchester will do and it will do it in a short action rifle. Larger game calls for bullets weighing from 150 to 160 gr. H4831, H450, H4350, H414, IMR-4350, and IMR-4831 are excellent powders for the .284 Winchester.These ballistics make it clear that the .284 Winchester is as good as the .280 Remington with the same weight bullet. Of course the short, handy mountain rifles for which the .284 Winchester seems best suited seldom come with 24 in barrels. Aside from Winchester, no other major company has ever loaded factory ammunition for the .284 Winchester.
The cartridge is sometimes used for long range target shooting like F-Class and 1000 yd/m long range competitions, where participants usually handload their 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...
. For this application the .284 Winchester is loaded with 175 and 180 gr very-low-drag bullets (vld).
The .284 Winchester is not popular in Europe, where it competes with the 7x64mm
7x64mm
The 7x64mm is a rimless bottlenecked centerfire cartridge developed for hunting. As is customary in European cartridges the 7 denotes the 7 mm bullet caliber and the 64 denotes the case length...
, to which it is almost ballistically identical. When compared to the .284 Winchester the 7×64mm has a lower C.I.P. maximum allowed chamber pressure and as a European 7 mm cartridge has a slightly larger bore. European 7 mm cartridges all have 7.24 mm (0.285 in) grooves Ø diameter. American 7 mm cartridges have 7.21 mm (0.284 in) grooves Ø.
Wildcats
While it has been occasionally factory chambered in various rifles, the chief reason for its survival has always been wildcatting. Wildcats are not governed by C.I.P. or SAAMI rules so wildcatters can capitalize on achievable high operating pressures. With the .284 Winchester as the parent case wildcatters have created 6mm-284, 6.5mm-284, .30-284, .338-284 and the .375-284 variants and the .475 Wildey Magnum.475 Wildey Magnum
The .475 Wildey Magnum is a semi-automatic pistol cartridge designed for big game hunting in the Wildey pistol.-History:The .475 Wildey Magnum was designed to be a hunting round. Cases are formed from .284 Winchester brass with the neck opened to take a .475" bullet, length is the same as the .45...
.
Today, the most popular and useful .284 Winchester-case based cartridge is not the original, but rather the 6.5-284 Norma. This former wildcat was developed for long range target shooting where participants usually handload their 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...
. It is currently one of the most used non-wildcat cartridges by match shooters in F-Class and 1000 yd/m benchrest long range competitions.
See also
- 7 mm-08 Remington7 mm-08 RemingtonThe 7mm-08 Remington is a rifle cartridge that is almost a direct copy of a wildcat cartridge developed around 1958 known as the 7mm/308. As these names would suggest, it is the .308 Winchester case necked down to accept 7 mm bullets with a small increase in case length...
- 7x57mm Mauser
- .280 Remington.280 RemingtonThe .280 Remington, also known as the 7 mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721 and 725 rifles. The .280 is based on the .30-06 Springfield necked down to accept 7 mm bullets, with the neck moved forward .050in...
- 7x64mm7x64mmThe 7x64mm is a rimless bottlenecked centerfire cartridge developed for hunting. As is customary in European cartridges the 7 denotes the 7 mm bullet caliber and the 64 denotes the case length...
- 7 mm Remington Magnum7 mm Remington MagnumThe 7mm Remington Magnum rifle cartridge was introduced as a commercially available round in 1962, along with the new Remington Model 700 bolt action rifle. It is a member of the belted magnum family that is directly derived from the venerable .375 H&H Magnum...
- List of rifle cartridges
- Delta L problemDelta L problemThe delta L problem is a condition that occurs regarding certain firearms chambers and their practical incompatibility with ammunition made for the corresponding chambering....