Capreolus Club member Mo Shiran explores whether the .300 WSM is the overlooked unicorn of modern cartridges, combining record-setting precision, versatile hunting performance, and efficient design, yet never achieving the popularity it seems to deserve.
In my previous article, “7mm PRC – An Intelligent Cartridge,” I highlighted some of the key attributes of the exciting new 7mm PRC and what makes it a true Precision Rifle Cartridge, a recipe shared across Hornady’s entire PRC range. But what if I told you there was a Precision Rifle Cartridge long before Hornady’s PRC line?
At the National Benchrest Shooting Association (NBRSA) match near Tucson, Arizona, on February 13, 2021, Charles Greer, aged 83, achieved one of the most remarkable feats in competitive benchrest shooting. He fired a 10-shot group at 1,000 yards that measured just 2.680 inches—equivalent to approximately 0.256 MOA. A record that remains intact to this day. His calibre of choice? The .300 Winchester Short Magnum (WSM).
Looking closely at some of the design features of the .300 WSM, there are clear similarities to the modern PRC cartridges: an efficient short and fat case, a steep shoulder angle, no belt, and the ability to be paired with heavy, high-BC bullets.
Winchester introduced the .300 WSM in 2000 with the aim of matching .300 Win. Mag. ballistics while taking advantage of a shorter case. With about 10% less powder, a more efficient burn rate, and reduced recoil, it offered a compelling balance. The .300 WSM is significantly shorter than its big brother, the .300 Win. Mag.—the SAAMI-specified overall cartridge length for the .300 WSM is 2.860 inches, just slightly longer than the .308 Winchester.
Figure 1 - Left to right: 300 Win Mag, 300 WSM, 308 Win
Let’s look at the ballistic performance of the .300 WSM against some popular hunting calibres in the UK, out to 300 yards. (Cartridges are compared with similar bullet weights where possible, using Hornady products to reduce variables.)
It’s not surprising that the .300 Win. Mag. remains king with its long case packed with powder, but the .300 WSM follows closely behind despite its shorter case. It’s also good to see my beloved 100-year-old .270 Winchester still holding its place in the rankings.
Practical Benefits
In addition to its impressive ballistics, another major advantage of the .300 WSM is its use of .30-calibre bullets. These strike a perfect balance: from light 100-grain varmint bullets to authoritative 250-grain projectiles. They offer deep penetration, reliable expansion, and effective terminal performance on everything from small to large game. No wonder Peter Jones is emotionally attached to his beloved .308 Winchester, its versatility is undeniable, and the .300 WSM builds on that same tradition.
Why Isn’t It More Popular?
So the .300 WSM holds a long distance precision record, has an efficient case design, fits into a short action, delivers impressive ballistics, uses versatile .30-calibre bullets for hunting and precision target shooting, and produces less recoil than the .300 Win. Mag. Did Winchester truly introduced a unicorn calibre? If yes, Why it is not very popular?
Shortly after its introduction, the .300 WSM was at the centre of a lawsuit brought by Rick Jamison. He held patents on short, fat cartridge designs and claimed that Winchester had infringed on his work. In 2005, after lengthy proceedings, Jamison won royalties from major ammunition and rifle makers. This significantly slowed the calibre’s early momentum and later expansion.
Today, rifle and ammunition availability for the .300 WSM in the UK remains limited. If you’re looking for a new rifle, you’ll most likely be restricted to options like the Tikka T3X or Steyr CL, both excellent choices. Ammunition, if you can find it, is expensive: expect to pay between £80–£100 for a box of 20.
My Verdict
Would I consider the .300 WSM for deer stalking and range shooting in the UK? Certainly, but with caveats. In its factory form, it’s arguably an overkill for most deer species here. The smaller .308 Winchester is far more suitable in that regard.
However, if you want a handy woodland carbine that maintains .308-like performance and are willing to hand-load, then the .300 WSM becomes a magic combination. My personal choice would be a Tikka T3X with the barrel cut to 18 inches and threaded for a moderator. For ammunition, I would hand-load a 165-grain Hornady CX monolithic bullet over 60 grains of Vihtavuori N540 (or a powder with a similar burn rate). QuickLOAD modelling shows this produces ballistic performance nearly identical to the .308 Winchester—but with the efficiency and modern advantages of the WSM design.
If you would like to get into deer stalking, then theres no better place to start than with the Proficient Deer Stalker Level 1( PDS1): Proficient Deer Stalking Course - PDS1
