The 7mm Shooting Times Westerner, sometimes referred to as the 7mm STW, began as a wildcat rifle cartridge developed by Layne Simpson in 1979. It is an 8mm Remington Magnum case that has been "necked down" (narrowing the case opening) by 1 mm to accept 7mm (.284 in) bullets. This cartridge is named after the magazine Shooting Times where Layne Simpson is a regular contributor.
| Specifications |
| Parent case |
8mm 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) |
| Case capacity |
93.3 gr of H2O |
| Rifling twist |
1 in 9 in (229 mm) |
| Primer type |
Large rifle magnum |
| Maximum pressure (SAAMI[1]) |
65,000 psi (450 MPa) |
| Ballistic performance |
| 160 gr (10 g) Partition |
3,177 ft/s (968 m/s) |
3,587 ft⋅lbf (4,863 J) |
Determined at checkout.
