All About the 7mm Cartridge

Long recognized as a superb choice for hunters, the 7mm (.284) bore size is now attracting great interest among long-range match shooters as well. The 7mm occupies the "sweet spot" between 6.5mm and 30 caliber--with an optimal balance between bullet weight and BC. It's hard to beat 7mm ballistics with either a 6.5mm or a reasonably-sized 30, and the 7mm will give longer barrel life than a 6.5 mm with less recoil than a 30-caliber (of equal BC). To match the ballistics of a 7mm 180gr VLD with a 30-caliber bullet, you must move up dramatically in bullet weight--to a 210gr or larger bullet. To drive the heavier 30-caliber bullet at similar velocities, you'll need more powder. More powder and a much heavier bullet weight means more recoil (and attendant fatigue) for the 30-caliber shooter. The combination of great ballistics with manageable recoil has made the 7mm cartridge a favorite among long-range prone and benchrest shooters. The chamberings of choice are the .284 Winchester, 7mm Winchester Short Magnum (7mm WSM), and 7mm Remington Short Action Ultra-Magnum (7mm SAUM). For silhouette shooters and hunters, the 7mm-08 is a top choice (but not the only choice).


7mm family portrait: (left to right) 7mm-08 Rem, 7mm Mauser, .284 Win, .280 Rem, 7mm SAUM, 7.21 Lazzeroni Tomahawk, 7mm WSM, 7mm Rem Mag, 7mm Wby Mag, 7mm Dakota, 7mm STW, 7mm Ultra Mag and 7.21 Lazzeroni Firebird.

New Interest in the .284 Winchester For many years, the "original" .284 Winchester lived in the shadow of the smaller 6.5-284. That is all changing. Today there is great interest in the .284 Win.

Charles Ballard used a 'straight .284' recently to win the 2008 F-Class Nationals convincingly. With its short, stubby case, and rebated rim, the .284 Winchester is a very efficient cartridge. With the latest high-BC 7mm bullets, the original .284 Winchester is proving tough competition for its 6.5-284 offspring. And now, with the introduction of Reloder 17, the .284 Win is capable of driving 180gr VLDs at nearly 3000 fps, a speed that once demanded a short magnum (or bigger) case.

7mm Short Magnum Options Speaking of short magnums... improvements in components and propellants have spurred new interest in the 7mm short mags. Among the short action magnums, most interest has focused on the 7mm WSM (and 300 WSM necked down to 7mm) until very recently. However, Norma has started producing 300 Rem SAUM brass, and that has sparked new interest in the 7mm SAUM. Read our report below and you'll see why the 7mm SAUM may just be a better choice than the WSM for 175-185gr bullets. Are there downsides to the fashionable Short Magnums? Yes. First, many shooters stepping up from a .308 Win or 6.5-284 find that a 7mm WSM pushing 180s at 3000+ fps beats them up during an extended match. The extra recoil takes its toll. The other "Achilles heel" of the Short Mags is barrel life. Make no mistake about it... hot-loaded Short Mags wear out barrels quickly. It's not unusual for a 7mm WSM to "go south" after just 700-900 rounds, though some barrels will last longer.

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