The .338 Ruger Compact Magnum (l.) and .375 Ruger are typical of the new magnums in that they deliver similar velocities to their long-action counterparts but in shorter actions and, in the case of the RCMs, much shorter barrels. The .370 Sako is basically a .30-06 on steroids, with the ability to launch a 286-grain bullet above 2,500 fps. The Barnes TSX (l.) and Super Solids were recovered from a Cape buffalo.

Of course, not all the new magnums are short, fat and rimless. The Remington Ultra Mags (7mm, .300, .338, .375) are full-length unbelted magnums that require a .375-length action. They are fatter than the belted magnums they emulate and therefore do have ignition and burning efficiency. They are unbelted, which saves magazine capacity space as well as allowing more precise headspacing. Each can appropriately be compared to an existing belted magnum (7mm STW, .300 Weatherby Magnum, .340 Weatherby Magnum, .375 Weatherby Magnum).

However, the Ultra Mags do have more powder capacity than any belted magnum counterpart (not counting the huge-cased .30-.378, .338-.378 and .378 Weatherby Magnums). So, at least theoretically, they can produce more velocity. So if you want speed, the Ultra Mags may be for you, but don't expect exponential gains. Velocity gains are at best incremental and depend somewhat on who is doing the loading.

I will concede that the Ultra Mags and John Lazzeroni's family of long, unbelted proprietary magnums aren't about packaging at all. They are about performance, and when loaded properly they're the fastest in their class.

By contrast, the Hornady-designed .308 Marlin Express and .338 Marlin Express rounds are about packaging. Both are short, fat, rimmed cartridges that provide unprecedented downrange performance from the all-American lever gun.

In any other action the cartridges wouldn't be impressive at all, but in their package--a tubular-magazine Marlin--they're hell on wheels. In fact, the new .338 Marlin Express is the first true, general purpose elk cartridge chambered in such a rifle. (Editor's note: See Wayne van Zwoll's article elsewhere in this issue).

There is one downside to packaging. It is not always easy to make the short, fat cartridges feed as well as those same actions fed with the longer, slimmer cartridges those actions were designed for. This is not a universal problem, but I have had far more feeding issues with short magnums than with all other cartridges put together.

So are you ready to trade Old Betsy? Maybe, but make sure you're making a wise choice. Velocity gains are minimal, and accuracy gains are elusive. And there are issues with any new cartridge.

One is availability. Not all of the new magnums have become popular, so the rifle you want may not be so chambered. For darn sure your local mom-and-pop gun shop cannot possibly stock all of the new cartridges. It will be many years, if ever, before any of the new magnums are as available as, say, the 7mm Remington Magnum, .300 Winchester Magnum or .375 H&H.

Being an astute rifleman, you may instantly answer, "No problem; I'll load my own." With whose data? An obvious advantage to any cartridge that has been popular for several generations is a rich body of loading data.

Information is scarce on new cartridges, and in some cases handloading may be a bit problematic. For instance, the 7mm Ultra Mag is fast and, for its performance, amazingly mild in recoil. But it is extremely overbore capacity, and there are few propellants that bring it to full performance with safe pressures.

In other cases, well, you simply can't do it. Federal's new .370 Sako Magnum is, essentially, the .30-06 case necked up to take a .366 (9.3mm) bullet, with a slightly longer case and a short neck. Federal used its High Energy propellant technology to get a 286-grain bullet above 2,500 fps, which is a .30-06 case on steroids. Handloaders may come reasonably close but will not equal this velocity with commercially available powders.