7 mm STW
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| 7 mm STW | ||
|---|---|---|
| Type | Rifle | |
| Place of origin | USA | |
| Production history | ||
| Designer | Layne Simpson | |
| Designed | 1979 | |
| Produced | 1989-Present | |
| Specifications | ||
| Parent case | 8 mm Remington Magnum | |
| Case type | Belted, bottleneck | |
| Bullet diameter | .284 in (7.2 mm) | |
| Neck diameter | .315 in (8.0 mm) | |
| Shoulder diameter | .4868 in (12.36 mm) | |
| Base diameter | .5126 in (13.02 mm) | |
| Rim diameter | .532 in (13.5 mm) | |
| Rim thickness | .220 in (5.6 mm) | |
| Case length | 2.850 in (72.4 mm) | |
| Overall length | 3.60 in (91 mm) | |
| Rifling twist | 9 | |
| Primer type | Large rifle magnum | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 120 gr (7.8 g) X | 3,384 ft/s (1,031 m/s) | 3,052 ft·lbf (4,138 J) |
| 140 gr (9.1 g) X | 3,268 ft/s (996 m/s) | 3,321 ft·lbf (4,503 J) |
| 150 gr (9.7 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 (11.3 g) PSPCL | 3,047 ft/s (929 m/s) | 3,609 ft·lbf (4,893 J) |
| Test barrel length: 26" Source: Accurate Powder [1] |
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The 7 mm STW (Shooting Times Westerner) began as a wildcat rifle cartridge developed by Layne Simpson in 1979.[2] It is an 8 mm Remington Magnum case that has been "necked down" (narrowing the case opening) by 1 mm to accept 7 mm (.284 in) bullets. This cartridge is named after the magazine Shooting Times where Layne Simpson is a regular contributor.
Contents |
[edit] Background
The 7mm STW graduated to commercial status when it was officially recognized by SAAMI in 1996.[3] Remington Arms Company was one of the first large ammunition companies to produce this cartridge in 1997, with others like Federal Cartridge Company, A-Square, and Speer also carrying it. All mass-market US riflemakers now offer a selection of production models chambered for the 7mm STW, which has established a reputation as a fine long-range deer and medium game rifle.
[edit] Performance
The only the commercial 7mm cartridge to have more power than the 7mm STW is the 7mm Remington Ultra Magnum.[3] Dimensionally and ballistically, there are similarities between the 7mm STW and the 6mm cartridge based on the .375 H&H Magnum case necked down, known as the .244 H&H Magnum.[citation needed]
[edit] See also
- 7mm calibre for other cartridges of this calibre.
[edit] References
- ^ "7 mm STW data" from Accurate Powder
- ^ "The 7mm STW (Shooting Times Westerner)" by Chuck Hawks
- ^ a b "The 7mm STW (Shooting Times Westerner)" by Chuck Hawks (subscription only)
