| 7 mm Winchester Short Magnum | ||
|---|---|---|
WSM and WSSM family of cartridges. From left to right: .223 WSSM, .243 WSSM, .25 WSSM, .270 WSM, 7 mm WSM, .300 WSM, .325 WSM. |
||
| Type | Rifle | |
| Place of origin | United States | |
| Production history | ||
| Designer | Winchester | |
| Designed | 2001 | |
| Specifications | ||
| Parent case | .404 Jeffery | |
| Case type | rebated rim, bottleneck | |
| Bullet diameter | 0.284 in (7.2 mm) | |
| Neck diameter | 0.321 in (8.2 mm) | |
| Shoulder diameter | 0.538 in (13.7 mm) | |
| Base diameter | 0.555 in (14.1 mm) | |
| Rim thickness | 0.535 in (13.6 mm) | |
| Case length | 2.100 in (53.3 mm) | |
| Rifling twist | 1 turn in 9.5" | |
| Primer type | large rifle magnum | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 160 gr (10 g) | 3,050 ft/s (930 m/s) | 3,304 ft·lbf (4,480 J) |
| Source(s): Winchester [1] | ||
The 7mm Winchester Short Magnum (also known as the 7mm WSM) is a centrefire cartridge developed in partnership with Browning Arms Company and Winchester ammunition, making its debut and introduced to the shooting public in 2001.
The 7mm WSM is based on the .300 WSM case necked down to handle .284" bullets. Winchester claims a muzzle velocity (MV) of 3,225 ft/s with a 140 grain bullet for their 7mm WSM cartridge; the claimed muzzle energy (ME) is 3,233 ft. lbs. With a 160 grain bullet the Winchester figures are 2990 ft/s and 3176 ft. lbs. at the muzzle. The lighter, shorter 7mm bullets are preferred in these short case magnums. [2]
The 7mm WSM cartridge achieves its useful purpose as an excellent cartridge for larger mule deer, sheep, black bear and elk.