This Alaskan brown bear fell to the .325 WSM, one of the new batch of short magnums.

The past few years have seen an astonishing array of new "magnum" cartridges come down the pike. Just to name a few, these have included Remington Ultra Mags and Short-Action Ultra Mags, Winchester Short Magnums and Super Short Magnums, Hornady's Ruger Compact Magnums and Federal's .370 Sako Magnum. And then there are new high-performance cartridges that are not called "magnums" but still provide the kind of performance we expect to get from a "magnum" such as the .308 Marlin Express and .338 Marlin Express rounds and the .375 Ruger and .416 Ruger cartridges.

With all of these new cartridges on the street, should we get rid of our tried-and-true favorites such as the 7mm Remington Magnum, the .300 H&H, the .338 Winchester Magnum or the .375 H&H? Maybe, maybe not. Before you consider such a move, however, you need to try to understand the new magnums. In short, what do these new magnums do that the old ones don't?

American riflemen have long been crazy about velocity and accuracy, but if you are considering switching to the new magnums because you think you can get more speed, forget it.

The first magnum craze of the late 1950s and 1960s was primarily about velocity, but even then the magnum cartridges from Winchester and Remington didn't do anything new because the practical limit of sporting rifle velocity had been explored by wildcatters back in the 1930s and implemented by Roy Weatherby in the 1940s. Weatherby's cartridges were good (and fast), and he was very good at marketing. It was almost certainly the growing popularity of Roy Weatherby's proprietary magnums that led to the glut of belted magnum cartridges back when I was a kid.

None of the new magnums, not a single one, reaches velocity levels that have not been reached before. Nor can they. Nitrocellulose powders still exit the bore at a bit over 5,000 fps, but bullets cannot reach this velocity because of friction within the bore.

Seventy-five years ago the .220 Swift broke the 4,000 fps barrier. That velocity has been equaled by a few varmint cartridges and by some wildcat and proprietary rounds--such as selected light-bullet loads in some of John Lazzeroni's cartridges. But considering pressure, barrel wear, recoil and sensible hunting bullet weights, 3,000 fps is still fast, and few hunting cartridges approach, let alone exceed, 3,500 fps. Trust me, nobody wants or needs a big bore at that velocity.

What about accuracy? Well, it is true that a short, fat case is conducive to accuracy because the primer's ability to ignite a larger percentage of the powder charge immediately creates an accuracy-enhancing burn curve. The same efficient burning also produces somewhat more energy per grain of powder burned, which is why cartridges such as the .300 RSAUM, .300 WSM and .300 RCM essentially equal the .300 Winchester Magnum but are able to equal it in much shorter cases loaded with considerably less powder.

Also, almost all of the new magnums are rimless and unbelted, meaning that they headspace on the shoulder, not on a belt. This tends to create more precise headspacing, which is also conducive to better accuracy.

The fallacy here is that, while the short (or long), fat, unbelted cartridges are conducive to accuracy, cartridge design is not the most important thing. Quality of barrel, mating of barrel to action, bedding and quality and consistency of ammunition are all more important factors in raw accuracy than cartridge design.