.300 Winchester Short Magnum Explained

300 Winchester Short Magnum
Origin:United States
Type:Rifle
Designer:Winchester
Design Date:2001
Manufacturer:Winchester
Production Date:2001–present
Case Type:Rebated-rimmed, bottleneck
Bullet:.308
Land:.300
Neck:.344
Shoulder:.538
Base:.555
Rim Dia:.535
Case Length:2.100
Length:2.860
Case Capacity:80.4 gr
Rifling:1-10"
Max Pressure:63817
Pressure Method:C.I.P.
Primer:Large rifle magnum
Bw1:150
Btype1:SP
Vel1:3313
En1:3657
Bw2:165
Btype2:HP
Vel2:3223
En2:3807
Bw3:180
Btype3:HP
Vel3:3095
En3:3830
Bw4:200
Btype4:SP
Vel4:2822
En4:3538
Test Barrel Length:24"
Balsrc:Reloading data at Accurate Powder

300 Winchester Short Magnum (also known as 300 WSM) is a .30 caliber rebated rim bottlenecked centerfire short magnum cartridge that was introduced in 2001 by Winchester.[1]

Specifications

The overall cartridge length is 72.6 mm. The cartridge case length is 53.34 mm. The bullet diameter is .308 in (7.82 mm), which is common to all U.S. .30 caliber cartridges. The principle at work in the short magnum cartridge is the fitting of larger volumes of powder in closer proximity to the primer's flash hole, resulting in more-uniform ignition. .300 WSM has a case capacity of 80 grains. The .30-06 Springfield holds 69 grains; .308 Winchester holds 56 grains; 30-30 Winchester holds 45 grains. The .300 Winchester Magnum has a case capacity of 93.8 grains. While providing ballistic performance nearly identical to that of the .300 Winchester Magnum, 300 WSM does this with about 14 grains less powder. The .300 WSM also head-spaces off of the case shoulder, versus the older .300 Winchester Magnum's belted head space design.

The advantage to this round is the ballistic performance is nearly identical to the .300 Winchester Magnum[2] in a lighter rifle with a shorter action burning 8 - 10% less gunpowder. A disadvantage of cartridge case designs with relatively large case head diameters lies in relatively high bolt thrust levels exerted on the locking mechanism of the employed firearm. Also, in small ring actions the larger chamber diameter removes more steel from the barrel tenon, making it weaker radially.

Use

The .300 WSM is adequate for hunting all big game including (but not limited to): moose, black bear, brown bear, elk, mule deer, and white-tailed deer in forests and plains where long range, flat shots are necessary. The .300 WSM is also used in benchrest shooting.

The .300 WSM has a standard bullet diameter of .308 in (7.82 mm) and takes advantage of the numerous bullet options available in that caliber.

Warnings

The 300 WSM is a Delta L problem cartridge, meaning it can present unexpected chambering and/or feeding problems. The Delta L problem article explains this problem in more detail. The .300 Remington Short Action Ultra Magnum has very similar cartridge dimensions but is not interchangeable.

Muzzle velocity

Comparison

300 WSM performance comparisons [3] ! Cartridge! Bullet Weight (gr)! Muzzle velocity (fps)! Muzzle energy (Ft-lbs)
300 WSM 20028223536
200 2790 3456
200 2850 3607
200 3060 4158
200 3154 4417
200 2569 2930

See also

External links

Notes and References

  1. http://www.chuckhawks.com/subscribers/rifle_cartridge_page/300WSM.htm The 300 WSM (Winchester Short Magnum) by Chuck Hawks (subscriptions req)
  2. Web site: .300 Winchester Short Magnum.
  3. Web site: Load guide for rifle and handgun . Accurate Powders . 1617 . 3.5.