Winchester Super Short Magnum
Encyclopedia
Winchester Super Short Magnum, or WSSM is a line of rebated rim
bottlenecked centerfire short magnum
cartridge
s introduced by the U.S. Repeating Arms Company
(Winchester Inc). It is a further development of the Winchester Short Magnum
concept utilizing smaller bullets, but still of a high velocity.
case. The new "super short" case was to be based on design principles currently proving successful in benchrest competition, such as the 6 mm PPC
and 6 mm BR Remington. In 2003 the first cartridges of this design, the .223
and .243
Winchester Super Short Magnums (WSSM), were introduced. The .25 WSSM
was added to the family in 2004.
None of the cartridges has managed to capture any large market share. This is likely due in part to the fact that all three cartridges have similar performance to existing popular cartridges. In addition, the .223 and .243 versions early on attained a reputation for being barrel burners. Concerns about short barrel life are a common problem for high-velocity cartridges, making the WSSM rounds no different than other high-velocity cartridges. To help mitigate the problem, Browning currently uses chrome-lined barrels on all of their guns chambered for .223 WSSM.
Another advantage is the action size. For example, if we compare the .25 WSSM to the .25-06 Remington
, we find that the .25-06 requires a .30-06 length action, commonly called a standard or long action. The .25 WSSM case which is almost a full inch shorter, can make use of an existing short action such as used by the .308 Winchester
family of cartridges. Some manufacturers have even created extra short actions to accommodate newer short rounds. The intrinsic accuracy benefits of a short, stiffer action over a long action are well-established principles of rifle design. The resulting rifle is smaller, lighter, more compact, and quicker handling as well.
Like any new case introduced, wildcatters like to see what they can do to make new cartridges. Two of the more notable children or offshoots of this case are the .325 Corbin, which is essentially an 8 mm WSSM, and the .22/40 SMc, which is essentially the .223 WSSM with an elliptical shoulder.
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...
bottlenecked centerfire short magnum
Magnum
Magnum may refer to several things:* Moses Magnum, a Marvel Comics villain*Magnum, P.I., a television series** Thomas Magnum, the lead character...
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...
s introduced by the U.S. Repeating Arms Company
U.S. Repeating Arms Company
The U.S. Repeating Arms Company. Inc. is the current business name of the Winchester Repeating Arms Company, famous for making Winchester rifles....
(Winchester Inc). It is a further development of the Winchester Short Magnum
Winchester Short Magnum
Winchester Short Magnum, or WSM, refers to a family of rebated rim bottlenecked centerfire short magnum cartridges developed in the early 2000s by the U.S. Repeating Arms Company, the maker of Winchester rifles and one of the oldest firearms manufacturers in the United States...
concept utilizing smaller bullets, but still of a high velocity.
History
Winchester and Browning partnered to create a new shorter version of the popular WSM (Winchester Short magnum)Winchester Short Magnum
Winchester Short Magnum, or WSM, refers to a family of rebated rim bottlenecked centerfire short magnum cartridges developed in the early 2000s by the U.S. Repeating Arms Company, the maker of Winchester rifles and one of the oldest firearms manufacturers in the United States...
case. The new "super short" case was to be based on design principles currently proving successful in benchrest competition, such as the 6 mm PPC
6 mm PPC
The 6 mm PPC , or 6 PPC as it is more often called, is a centerfire rifle cartridge used almost exclusively for benchrest shooting. At distances out to 300 yards, it is one of the most accurate cartridges available...
and 6 mm BR Remington. In 2003 the first cartridges of this design, the .223
.223 WSSM
The .223 WSSM is a .224 caliber rifle cartridge created by Winchester and Browning based on a shortened version of the Winchester Short Magnum case.- History :...
and .243
.243 WSSM
The 243 Winchester Super Short Magnum or 243 WSSM is a rifle cartridge introduced in 2003. It uses a .300 WSM case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of...
Winchester Super Short Magnums (WSSM), were introduced. The .25 WSSM
.25 WSSM
The .25 Winchester Super Short Magnum is a third member of the Winchester Super Short Magnum cartridge family created by Winchester and Browning. It is the largest caliber of the WSSM's and is the most capable of handling large game such as deer and wild boar.It is a necked-up version of the .243...
was added to the family in 2004.
None of the cartridges has managed to capture any large market share. This is likely due in part to the fact that all three cartridges have similar performance to existing popular cartridges. In addition, the .223 and .243 versions early on attained a reputation for being barrel burners. Concerns about short barrel life are a common problem for high-velocity cartridges, making the WSSM rounds no different than other high-velocity cartridges. To help mitigate the problem, Browning currently uses chrome-lined barrels on all of their guns chambered for .223 WSSM.
Advantages
There are basic advantages inherent to the Short Magnum concept. The idea is that the short, fat powder column gives a more uniform load density and ignition rate and therefore a more consistent burn. This in turn should translate into improved accuracy and potentially moderate recoil due to more efficient use of propellants.Another advantage is the action size. For example, if we compare the .25 WSSM to the .25-06 Remington
.25-06 Remington
The .25-06 Remington had been a wildcat cartridge for half a century before being standardized by Remington in 1969. It is based on the .30-06 Springfield cartridge necked-down to .257 inch caliber with no other changes...
, we find that the .25-06 requires a .30-06 length action, commonly called a standard or long action. The .25 WSSM case which is almost a full inch shorter, can make use of an existing short action such as used by 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...
family of cartridges. Some manufacturers have even created extra short actions to accommodate newer short rounds. The intrinsic accuracy benefits of a short, stiffer action over a long action are well-established principles of rifle design. The resulting rifle is smaller, lighter, more compact, and quicker handling as well.
Disadvantages
The fat cases reduce magazine capacity and negate their usefulness in military battle rifles.Cartridge Family
The cartridges in this family are, in order of development:| Name | Year | Bullet diameter | Notes |
|---|---|---|---|
| .223 WSSM .223 WSSM The .223 WSSM is a .224 caliber rifle cartridge created by Winchester and Browning based on a shortened version of the Winchester Short Magnum case.- History :... |
2002 | .224 in. (5.69 mm) | performance similar to .220 Swift .220 Swift The .220 Swift is a semi-rimmed rifle cartridge developed by Winchester and introduced in 1935. It was the first factory loaded rifle cartridge with a muzzle velocity of over... |
| .243 WSSM .243 WSSM The 243 Winchester Super Short Magnum or 243 WSSM is a rifle cartridge introduced in 2003. It uses a .300 WSM case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of... |
2003 | .243 in. (6.17 mm) | performance similar to 6 mm Remington 6 mm Remington The 6mm Remington was introduced by Remington Arms Company in 1955 as the .244 Remington. It is based on necking down the .257 Roberts. Originally intended as a Varmint and predator cartridge, the .244 was never factory loaded with bullets over 90 grains. Rifles marked .244 Remington have a 1 in ... |
| .25 WSSM .25 WSSM The .25 Winchester Super Short Magnum is a third member of the Winchester Super Short Magnum cartridge family created by Winchester and Browning. It is the largest caliber of the WSSM's and is the most capable of handling large game such as deer and wild boar.It is a necked-up version of the .243... |
2004 | .257 in. (6.53 mm) | performance similar to .257 Roberts .257 Roberts The .257 Roberts a medium powered .25 caliber cartridge known affectionately as the Bob. It has been described as the best compromise between the low recoil and flat trajectory of smaller calibers such as the .22 and 6mm, and the strong energy but not the strong recoil of larger popular hunting... and .25-06 Remington .25-06 Remington The .25-06 Remington had been a wildcat cartridge for half a century before being standardized by Remington in 1969. It is based on the .30-06 Springfield cartridge necked-down to .257 inch caliber with no other changes... |
Like any new case introduced, wildcatters like to see what they can do to make new cartridges. Two of the more notable children or offshoots of this case are the .325 Corbin, which is essentially an 8 mm WSSM, and the .22/40 SMc, which is essentially the .223 WSSM with an elliptical shoulder.