Wildcat rifle cartridge
7mm Shooting Times Westerner |
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Type | Rifle |
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Place of origin | United States |
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Designer | Layne Simpson |
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Designed | 1979 |
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Produced | 1989-Present |
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Parent case | 8mm Remington Magnum |
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Case type | Belted, bottleneck |
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Bullet diameter | .284 in (7.2 mm) |
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Neck diameter | .315 in (8.0 mm) |
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Shoulder diameter | .4868 in (12.36 mm) |
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Base diameter | .5126 in (13.02 mm) |
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Rim diameter | .532 in (13.5 mm) |
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Rim thickness | .220 in (5.6 mm) |
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Case length | 2.850 in (72.4 mm) |
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Overall length | 3.60 in (91 mm) |
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Case capacity | 93.3 gr of H2O |
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Rifling twist | 1 in 9 in (229 mm) |
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Primer type | Large rifle magnum |
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Maximum pressure (SAAMI[1]) | 65,000 psi (450 MPa) |
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Bullet mass/type |
Velocity |
Energy |
120 gr (8 g) X |
3,384 ft/s (1,031 m/s) |
3,052 ft⋅lbf (4,138 J) |
140 gr (9 g) X |
3,268 ft/s (996 m/s) |
3,321 ft⋅lbf (4,503 J) |
150 gr (10 g) BT |
3,233 ft/s (985 m/s) |
3,482 ft⋅lbf (4,721 J) |
160 gr (10 g) Partition |
3,177 ft/s (968 m/s) |
3,587 ft⋅lbf (4,863 J) |
175 gr (11 g) PSPCL |
3,047 ft/s (929 m/s) |
3,609 ft⋅lbf (4,893 J) |
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Test barrel length: 26" Source(s): Accurate Powder [2] |
The 7mm Shooting Times Westerner, sometimes referred to as the 7mm STW, began as a wildcat rifle cartridge developed by Layne Simpson, Field Editor of Shooting Times, in 1979.[3] It is an 8mm Remington Magnum case that has been "necked down" (narrowing the case opening) by 1 mm to accept 7 mm (.284 in) bullets.[4]
Background
The first major company to produce the 7mm STW was A-Square in 1994.[5] The 7mm STW graduated to commercial status when it was officially recognized by SAAMI in 1996,[6] and the Remington Arms Company started to produce it in 1997,[7] with other ammunition manufacturers following. As of 2019, Federal Premium Ammunition is the only major manufacturer to still offer it on a regular basis, but smaller manufacturers also provide loaded ammunition.[8]
See also
References