The 270 Winchester Short Magnum
or 270 WSM is a short, unbelted, magnum cartridge created by necking down the .300 Winchester Short Magnum and fitting it with a .277 caliber bullet. The correct name for the cartridge, as listed by the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI), is 270 WSM, without a decimal point.3 It is a member of the Winchester Short Magnum family of cartridges.
270 Winchester Short Magnum
270 WSM cartridge
Type
Rifle
Production history
Designer
Winchester.
Bullet diameter
.277 in (7.0 mm)
Neck diameter
.3140 in (7.98 mm)
Shoulder diameter
.5381 in (13.67 mm)
Base diameter
.5550 in (14.10 mm)
Rim diameter
.535 in (13.6 mm)
Rim thickness
.054 in (1.4 mm)
Case length
2.100 in (53.3 mm)
Overall length
2.860 in (72.6 mm)
Rifling twist
1-10″
Primer type
Large rifle magnum
Maximum pressure
65,000 psi (450 MPa)
Ballistic performance
Bullet mass/type
Velocity
Energy
90 gr (6 g) JHP
3,700 ft/s (1,100 m/s)
2,737 ft⋅lbf (3,711 J)
130 gr (8 g) HP
3,295 ft/s (1,004 m/s)
3,135 ft⋅lbf (4,250 J)
140 gr (9 g) SP
3,250 ft/s (990 m/s)
3,284 ft⋅lbf (4,453 J)
150 gr (10 g) SPBT
3,136 ft/s (956 m/s)
3,276 ft⋅lbf (4,442 J)
History
Following the immediate success of the .300 WSM in 2001, the .270 and 7mm WSM were introduced in 2002. The last of these cartridges, the .325 WSM, was introduced in 2005.270 winchester short magnum
Like its siblings, the .270 WSM has gained a steady following for a variety of reasons. One of the foremost factors in the success of these cartridges has been the reduction in both size and weight of rifles in comparison to traditional magnum chamberings. The .270 WSM has also given fans of the .270 Winchester a cartridge which boasts greatly enhanced performance supported by readily available factory ammunition.270 winchester short magnum
These cartridges have quickly became popular world wide, with a variety of ammunition found in gun stores around the world. The WSM’s have also received a small amount of negative criticism. Poor magazine to chamber feeding and excessive pressures resulting in difficult extraction have been major complaints. Both of these issues have been addressed at a design level. The most recent of complaints has been the cost of ammunition, ever rising due to metal market demands in developing nations.270 winchester short magnum
The .270 WSM is the third in what is now called the trio of .270 (.277”) caliber commercial cartridges. These include the .270 Winchester, .270 WSM and the .270 Weatherby Magnu
270 winchester short magnum
Federal Power-Shok Ammunition 270 Winchester Short Magnum (WSM) 130 Grain Soft Point 250 rounds
270 winchester short magnum
270 winchester short magnum
270 winchester short magnum
Winchester DEER SEASON XP .300 AAC Blackout 150 grain Extreme Point Polymer Tip 500 rounds
270 winchester short magnum
270 winchester short magnum