Cutting magnums down to size
—John Zent, Editorial Director
The Ruger Compact Magnums are the latest chapter in a thread of development for a short-action-length round that is surprisingly powerful, yet provides the superior accuracy potential many have believed is inherent to short, wide powder columns. This thread continued somewhat sporadically in four noticeable stages.
First came the .284 Win. and the .350 Rem. Mag., oddballs in the bigger-is-better 1960s. Their identical 2.170" case length was just a shade longer than the short-action standard, the .308 Win., but at 0.500+" case diameter, both were considerably fatter. While 140-gr.284 velocities are comparable to that of the .308s, downrange energy and trajectory of .284 loadings beat 150-gr. .308 loads by 10 percent or more. The .350 Rem. distinguished itself by shooting heavier bullets—up to 300 grs.—with larger frontal areas, and because it was offered only in carbine-length rifles for several years it was mostly typecast as a short-range proposition for bears or moose.
This early pair didn’t entirely escape notice, but if one desired something more exotic than the .270 Win., .308 Win. or .30-’06 Sprg., faster belted magnums were in their heyday. Critics were confounded by the .284’s rebated rim and, because of its sharply angled shoulders, feeding difficulties were common. In less than 20 years major gunmakers discontinued the chamberings. Both live on in custom rifles and have attracted cult followings that keep original guns selling for more than they cost new. Ironically, the current favorite of many NRA High Power shooters is the necked-down 6.5-284 Norma.
Over the next two decades, the short-case thread was hijacked by benchrest devotees who pushed a pair of wildcat families to commercial status. Remington jumped in first, offering its BR trio in .22, 6 mm and 7 mm. Later, European makers Sako and Norma would counter with the .22 and 6 mm PPC cartridges. The latter were pointedly marketed to varmint shooters seeking to attain benchrest-level accuracy. Talk about short and stubby, case dimensions for the 6 mms were approximately 1.5"x 0.45", yet both easily pushed bullet weights up to 90 grs. faster than 3000 f.p.s., thereby approaching .243 Win. performance. While Remington BR and PPCs never really transferred their benchrest dominance to popularity afield, their exaggerated case profile introduced many American shooters to the short, fat, accurate concept.
In 2000 Winchester launched a campaign to bring short-cased magnums into big-game prominence, and Remington quickly followed suit. Soon we greeted a stream of stubby contenders including four Winchester Short Magnums (WSM), two or three Winchester Super Short Magnums (WSSM) and two Remington Short-Action Ultra Magnums (SAUM). WSM case dimensions are 0.555" at the base/2.10" length. The SAUMs are slightly thinner and shorter at 0.550" base/2.015" length.
The first among these in order of appearance and popularity is the .300 WSM, which lived up to promises that it would run neck-and-neck with the popular .300 Win. Mag. With 180-gr. spitzers, both the .300 WSM and .300 SAUM reach 3000 f.p.s. and deliver downrange energies on par with comparable long-cased magnums.
These cartridge families appear to be here to stay simply because of the number of rifles that have been sold, especially in .270 and .300 WSM. At some point loaded ammunition for several of the least popular calibers may become hard to find, and certain chamberings will likely be dropped from commercial production. Some folks contend that feeding problems have been inherited by this generation, and the WSSMs in particular, have been criticized for high pressures and short barrel life. A contentious lawsuit over patent infringement issues within this category has also clouded the picture, and as a result some manufacturers have shied away from these calibers. Conversely, most owners we’ve heard from are satisfied and plenty of game is currently being taken by WSMs and SAUMs.