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Behind the Bullet: .270 Winchester Short Magnum

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The middle of the 20th century saw a definite shift in cartridge design; the improvements in powder and metallurgy allowed for smaller packages. Winchester shortened the H&H case to fit in a long-action receiver, offering their quartet of new magnum cartridges, Remington took things even further by cutting the belted case down to fit in the short-action receiver in their 6.5 and .350 Remington Magnums, and even the U.S. Army moved beyond the beloved .30-06 Springfield for the shorter 7.62×51 NATO, better known to us hunters as the .308 Winchester. Looking back, the .308 Winchester and its offspring surely gained a huge following, as did the .300 Winchester Magnum and .338 Winchester Magnum, and the .458 Winchester Magnum, however the Remington shorties have all but faded into obscurity.

Three cartridges of .270 Winchester Short Magnum ammunition lined up on wooden table top.

The new century saw a rebirth of the short magnum concept, with Winchester introducing the .300 Winchester Short Magnum (WSM). Designed to mimic the performance of the earlier (and belted) .300 Winchester Magnum, the WSM family had a bit of a sordid past, including a legal battle between Winchester and Rick Jamison, but made a considerable splash in the industry. The case was loosely based on the beltless .404 Jeffery, but shortened to 2.100 inches long, using a 35-degree shoulder to handle headspace duties.

In 2002, just one year after the release of the .300 WSM, Winchester announced the .270 WSM; it was the first commercial cartridge released in the .277-inch bore diameter since the .270 Weatherby Magnum came onto the market in 1945, twenty years after Winchester released the .270 Winchester. Keeping the same 35-degree shoulder as the .300 WSM, and offering a neck of one-caliber in length, the .270 WSM would better the velocities of the .270 Winchester, in a shorter and lighter rifle.

The .270 WSM was the second in the series—which would go on to include the 7mm WSM and the .325 WSM, and later the even-shorter .25, .243 and .223 WSSMs—but is the only member of the family to maintain a following. It will better the velocity of the .270 Winchester by 100 to 200 fps, though the two cartridges share the same bullet weights, generally topping out at 150 grains, due to the 1:10-inch twist rate common to most rifles chambered for the Winchester cartridges.

Ammunition reloading supplies on plastic table.

The 130-grain loads have a muzzle velocity ranging between 3150 fps and 3280 fps, depending on the manufacturer, and the 150-grain loads run between 3080 fps and 3120 fps, with the two loads generating over 3,000 ft.-lbs. of energy at the muzzle, making the .270 WSM a good choice for an all-around rifle for the majority of big game species, save the heavyweights and pachyderms. Looking at Federal’s 130-grain Nosler AccuBond load—leaving the muzzle at 3250 fps—and using a 200-yard zero, you’ll see that bullet hit 5.6 inches low at 300 yards, and 16.3 inches low at 400 yards; should you push matters to 500 yards you’ll need just over 33 inches of elevation. It also fares well in the wind; in a 10 mph crosswind you’ll need 5.6 inches of correction at 300 yards and 10.8 inches at 400 yards. Switch the projectile to the 150-grain Nosler Partition at 3100 fps, and you’ll see the trajectory drop by a couple inches, but still giving a very useful set of statistics. If you prefer the additional sectional density of the 150-grain slugs, there’s no drastic handicap to the trajectory within reasonable hunting distances.

There are good choices for factory loaded ammunition for the .270 WSM, including Winchester’s Deer Season Copper Impact and Expedition Big Game, Browning’s BXR and BXC loads, Federal’s Power-Shok (blue box) softpoint load, their Swift Scirocco II load and Trophy Copper load, as well as their 140-grain Berger Hybrid Hunter load and Fusion bonded core load, and Hornady’s Precision Hunter and Outfitter lines.

For those who choose to handload the .270 WSM, there are plenty of excellent bullet designs to choose from, including the Nosler AccuBond Long Range, Ballistic Tip and Partition, Swift A-Frame and Scirocco II, Federal Fusion, Trophy Bonded Tip and Terminal Ascent, Barnes TSX, TTSX and LRX and many more. Look to a large rifle magnum primer, and powders like IMR 4350, H4831SC and RL-19 and RL-22; I had excellent results with the latter.

Federal Premium .270 WSM ammunition.

While the .270 WSM remains a popular choice, I do think it faces a threat from the new 6.8 Western, that being a Winchester/Browning collaboration. The 6.8 Western is based on the .270 WSM, yet again shortened a bit, but designed to work with a faster twist rate (1:7.5 or 1:8, depending on rifle manufacturer) so it can use heavier bullets. The 162-grain Copper Impact, the 165-grain Nosler AccuBond Long Range and the 175-grain Sierra Tipped GameKing loads all put the .277-inch bore diameter in a new light, giving unprecedented ballistic coefficient and sectional density values. In my opinion, the 6.8 Western is everything the .270 WSM should have been from the drawing board, rather than just the velocity boost and short-action rifles.

Nonetheless, for the majority of tasks a hunter would ask of the .270 WSM, it is very well suited. I do favor premium bullets for the speedy cartridge, especially if the majority if your shots will come inside of 150 yards; the high impact velocity can put a strain on a standard cup-and-core bullet at deer woods distances.

While many of the WSM and WSSM cartridges have certainly faded, I think the .300 WSM and .270 WSM will continue for decades to come; American hunters just love the .270s, and the .270 WSM has caught on well enough to stick around.

Looking for previous installments of our “Behind the Bullet” series? We’ve got you covered.
• 360 Buckhammer
• 30 Nosler
• 7-30 Waters
• .370 Sako Magnum
• .17 HMR
• 6.5 Weatherby RPM
• .327 Federal Magnum
• .450 Bushmaster
• 7mm PRC
• .275 Rigby
• .340 Weatherby Magnum
• .416 Ruger
• 27 Nosler
• .257 Roberts
• 7mm Weatherby Magnum
 .300 PRC
• .350 Rigby Magnum
• .450 Nitro Express
• .17 Hornet
• 7mm STW
• 6.8 Western
• .375 Ruger
• .223 Remington
• 6.5×55 Swedish
• .416 Remington Magnum
• .300 Winchester Short Magnum
• 28 Nosler
• 6.5 PRC
• .22 WMR
• .458 Winchester Magnum
• .204 Ruger
• .22 Hornet
• .280 Ackley Improved
• .240 Weatherby Magnum
• .458 Lott
• .264 Winchester Magnum
• .348 Winchester
• 33 Nosler
• .260 Remington
• .30-30 Winchester
• .416 Rigby
 .358 Norma Magnum
• .22 LR
• 7mm-08 Remington
• 8mm Remington Magnum
• .338 Federal
• .224 Valkyrie
• .338-06 A-Square
• 9.3x62mm Mauser
• .257 Weatherby Magnum
• .45-70 Government
• .300 H&H Magnum
• .25-06 Remington
• .30-06 Springfield
• 6.5 Creedmoor
• .300 Remington Ultra Magnum
• 7mm Remington Magnum
• .470 Nitro Express
• .280 Remington
• .300 Winchester Magnum
• .270 Winchester
• .222 Remington
• .45 ACP
• .404 Jeffery
• .44 Remington Magnum
• .41 Remington Magnum
• .243 Winchester
• .338 Winchester Magnum
• .357 S&W Magnum
• 6.5-284 Norma
• 8×57 Mauser
• .38 Smith & Wesson Special
• 7x57mm Mauser
• 9mm Luger
• .35 Whelen
• .454 Casull
• .375 H&H Magnum
• .45 Colt
• .22-250 Remington
• 10mm Auto
• .308 Winchester

Article by PHILIP MASSARO

 

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