Ammo Brief: The Whopping ‘Little’.300 WSM

Ammo Brief: The Whopping ‘Little’.300 WSM

The relatively new .300 WSM offers the best of both worlds — power and efficiency.

Short and fast on this smoking short magnum: 

  • The .300 Winchester Short Magnum was introduced in 2000.
  • Initially, it was chambered in short, light Browning and Winchester rifles.
  • The .300 WSM duplicates .300 Win. Mag. velocities, while consuming about 10 percent less powder.
  • At one point, it and other WSM cartridges were embroiled in a legal battle over intellectual property infringements.
  • This, in part, stifled some Winchester Super Short Magnum's popularity.
  • Though, the .300 WSM developed a robust following.

Introduced in 2000 and chambered in short, light Browning and Winchester rifles, the .300 Winchester Short Magnum demonstrated a remarkably accurate ability to duplicate .300 Win. Mag. velocities, while consuming about 10 percent less powder.

The .300 WSM, an original Winchester design, fits handily into bolt-actions sized for a cartridge length of 2.860 inches. For highly efficient and consistent powder burning, the .300 WSM has a short-fat powder column geometry, a concept revered by accuracy-obsessed benchrest shooters for nearly three decades.

This cartridge — and all its Winchester Short Magnum siblings — became embroiled in a legal battle, and the end result was a less than enthusiastic appeal on the part of other manufacturers to offer rifles and/or ammunition for sale. However, unlike the Winchester Super Short Magnums that are collecting dust on the shelves or in shooters’ gun racks, the WSM line still enjoys moderate appeal, especially the .270 and .300 offerings.


Editor's Note: This article originally appeared in the April 2018 issue of Gun Digest the Magazine.


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  1. WSM are great. Too bad they aren’t more popular. The 300 will survive;at least for a while. Maybe even the .270. Too bad the 8mm(.325) isn’t appreciated more. With so many new cartridges coming out many may have an ever harder challenge to survive. Winchester was a bit early to the punch so to speak. Not long after the WSM family of cartridges came out, the shooting community became obsessed with long heavy for caliber aerodynamic high BC projectiles shooting through fast(low) twist rate barrels. Winchester missed that boat with the WSM family. The only part they got right with the current trend is a short,fat straighter walled cartridge with a steep shoulder angle. It is what it is. One can always reload. I got two 325wsm rifles and will keep them. I can always do a barrel switch if they lose their appeal to me. One positive note is that long range 1000 yard records have been set with long barreled (30”) heavy aerodynamic bullets(.210-.215) with the 300wsm.
    Apparently they are good enough to be effective at long range one way or another. Besides, at long range, many cartridges need a longer(and heavier) barrel than the norm to achieve their ultimate performance. I’m a fan of the WSM cartridges. 270wsm holds it own
    against the 7mm Rem.Mag too. Shame they all aren’t more popular. With all the new stuff coming out their future may be bleak.


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