.270 Winchester Short Magnum

270 Winchester Short Magnum

270 WSM cartridge

Type

Rifle

Place of origin

USA

Production history

Designer

Winchester

Designed

2002

Produced

2002

Specifications

Parent case

.300 WSM

Case type

Rimless, bottleneck

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 weight/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)

Test barrel length: 24"
Source(s): "Shooting Times" ^[1] / Accurate Powder ^[2]

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]

Overview

When it was introduced, the 300 WSM sported a new case that showed a lot of promise for uses in other calibers. In 2002 Winchester introduced new cartridges in its Winchester Short Magnum family, including the 7 mm WSM and 270 WSM. This new .270 cartridge was the third commercial .270 ever produced, and the first one in 60 years.^[1]

The 270 WSM is an improvement over the older 270 Winchester providing higher velocity with bullets of the same weight, and thus a flatter trajectory and more energy. Velocities tend to be about 250 ft/s (76 m/s) faster, in a cartridge that is shorter and can therefore be used in a shorter action for a more compact rifle if desired.

References

1 2 Pearce, Lane (October 2007). "Nosler's Model 48 Sporter and the .270 WSM". Shooting Times 48 (10): 44–46.
↑ "270 WSM reloading data" from Accurate Powder
↑ Sporting Arms and Ammunition Manufacturers' Institute

External links

The 270 WSM by Chuck Hawks
270 WSM Accuracy in Browning X-Bolt

Winchester firearms and cartridges

Rifles

Lever-action	Henry rifle Model 1866 Model 1873 Model 1876 Model 1886 Model 1892 Model 1894 Model 1895 Model 53 Model 55 Model 64 Model 65 Model 71 Model 88 Model 150 Model 250 Model 255 Model 9422

Bolt-action	Model 1878 Hotchkiss Model 1895 Lee Navy Model 1900 Model 1902 Model 1904 Model 43 Model 47 Model 51 Imperial Model 52 Model 54 Model 56 Model 57 Model 58 Model 59 Model 60 Model 60A Model 67 Model 68 Model 69 Model 70 Model 72 Model 75 Model 121 Model 131 Model 141 Model 320 Model 325 Model 670 Model 770

Pump-action	Model 1890 Model 1906 Model 61 Model 62 Model 62A Model 270

Semi-automatic	Model 1903 Model 1905 Model 1907 Model 1910 Model 30 Model 63 Model 74 Model 77 Model 100 Model 190 Model 490

Full-automatic	Olin/Winchester FAL Model 1917

Falling-block action	Model 1885

Shotguns

Pump-action	Model 1893 Model 1897 Model 1912 Model 25 Model 42 Model 1200 Model 1300

Lever-action	Model 1887 Model 1901 Model 9410

Single-shot	Model 20 Model 36 Model 37 Model 37A Model 41

Double-barrel	Model 21 Model 24 Model 96 Model 101

Semi-automatic	Model 1911 SL Model 40 Model 50 Model 59 Model 1400 Model 1500 SX-1

Cartridges

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.270 Winchester Short Magnum

Overview

See also

References

External links