Because RCMs are loaded to deliver high performance in short barrels, you can carry a lighter, handier, faster rifle without compromising bullet speed or energy.

The RCMs are designed to shine in short barrels that many hunters like to tote in the field. A rifle chambered to these rounds and fitted with a 20-inch barrel will make a handy powerhouse.

The notion of high velocities from short cases is hardly new. It dates not to the Winchester Short Magnums of the 1990s but to the .250/3000 developed for Savage by Charles Newton in 1912.

You might say the .308 Winchester and its offspring carried the idea a ballistic step farther. The belted magnums of the 1950s and early 1960s were for a time called short magnums because they bottled the hubris of the .300 Holland & Holland in cases configured for .30-06-length actions.

But Hornady's new short-magnum cartridges are the first to add short barrels to a list of reasons to buy another rifle. Ruger Compact Magnums are tailored to the compact rifles most hunters like to carry. They're comfortable to shoot and as accurate as I had hoped.

"Short barrels are stiff barrels," Emary reminds me. "We often get the tightest groups from rifles with short tubes."

Easier to maneuver in brush and on the steeps, 20-inch barrels also reduce overall rifle weight and lend themselves to full-length stocks. What's not to like about cartridges that accelerate in short barrels to velocities traditionally possible only in long ones?

The success of these Ruger Compact Magnums at market will no doubt influence the development of others. "We've already considered additional designs," Mittelstaedt hints.

What about rifles? Is Ruger secretly building up a supply of 77s chambered to the .300 and .388 RCMs? "We have nothing to do with rifle production," Emary says with a smile.

The .338 RCM case is shorter than its smaller brother's so it can use the cannelured bullets popular for the .338 Winchester Magnum.

I suspect by the time you read this, Ruger will have tipped its hand--and my request for a carbine-barreled .338 RCM will be working its way to the production line.

Will the new cartridges succeed? The Winchester Short Magnum line of cartridges has a big following among hunters. The .270 and .300, I'm told, have been particularly well received. According to Winchester reports, even the .325 WSM has exceeded initial sales targets.

Remington's Short-Action Ultra Mags, by some measures superior, have fared less well--mainly, I believe, because Remington chose to promote full-length Ultra Mags for a year while Winchester launched its WSMs. Starting second doesn't always mean you'll finish second, but in this case Winchester never gave up its advantage.

While these short magnums have fine records afield, the Ruger Compact Magnums present a formidable challenge. How will the hunting public rank the superior short-barrel performance of the RCMs against slightly higher velocities from WSMs in standard barrels? That's for you to decide.