Everybody hates to be wrong. In this case I especially hate it because I was wrong in front of every G&A reader. Well, OK, I wasn't totally wrong. In the October issue--in my story on trends in cartridge development--I predicted that the .375 Ruger case would be used as a platform for future cartridges. Well, at least I got that right. But I was wrong about the form these cartridges might take, and I was wrong about both caliber and length.

The author took this nice Colorado bull with a wildcat .338 WSM. Many .338 fans have been hoping for a factory short .33 that would replicate the .338 Winchester in a shorter, lighter rifle. Looks like that's happened with the .338 RCM.

I believed that the .30- and .33-caliber niches were plenty full, and I also thought that we had enough short, stubby cartridges. Obviously, I didn't talk to my friends at Hornady. The first two factory cartridges to use the .375 Ruger case are the .300 and .338 Ruger Compact Magnums. Both use the .375 Ruger case shortened to 2.015 inches and necked to accept, respectively, .308- and .338-inch bullets.

Is it OK to be wrong if the result is good? I hope so because these are both superb little cartridges. We got our first look at them last summer at PASA Park near Barry, Illinois. In a future issue my colleague Wayne van Zwoll will focus on the .300, while I'll concentrate on the .338 RCM.

Why a .33?
OK, the Gold Standard .33-caliber cartridge is the .338 Winchester Magnum, introduced in 1958 in a version of Winchester's Model 70 called the Alaskan.

Truthfully, the .338 was a bit slow on the uptake. Once you get over .30-caliber the market will always be a bit more limited, and with their heavier bullets, fast .33s kick a whole lot more than our other favorites. On the other hand, over time American hunters learned that, with heavier bullets and greater frontal area, a .338 would do a whole lot more. Push an aerodynamic .338 bullet fast enough and it is versatile enough for everything in North America.

The .338 RCM (left) with its parent case, the .375 Ruger (right). External dimensions remain similar, with the case shortened to 2.015 inches and necked down to accept a .338-inch bullet.

However, no .338-caliber cartridge is really needed for any deer hunting. Where the caliber shines is on larger game. To my thinking Elmer Keith was right: The .338 is the quintessential elk caliber. Slowly, over the years American hunters embraced it, and today the .338 is a favorite not only for elk but also for moose and bear (and it's superb for the full range of African plains game).

In order for any given caliber to maintain lasting popularity it must have a selection of good bullets. To some extent this is a "chicken or egg" dilemma. A caliber must be popular enough to warrant bullet development, but without plenty of good bullets its popularity will be limited. As I said, the .338 Winchester Magnum came on slowly, but it's endured for 50 years and there are plenty of good bullets. In addition to greater weight and frontal area, the classic .338 bullet weights have other attributes.

The fast bullets, generally intended for lighter game, average about 200 grains. A 200-grain .338 bullet has a Sectional Density of .250, considerably exceeding the .226 SD of the 150-grain .308 bullet and comparing well with the 165-grain .308 bullet's SD of .248. The general-purpose 225-grain bullet--plenty adequate for any elk or moose that walks--has an SD of .281, which exceeds the .271 SD of the 180-grain .30-caliber bullet.

Then there's the 250-grain heavyweight, with a very high SD of .313. Note that this exceeds the .305 SD of the 300-grain .375 bullet. And, yes, it's true: With greater SD and less resistance (because of smaller diameter), if bullet construction is equal a 250-grain .338 will always outpenetrate a 300-grain .375. This, plus their versatility, is why I believe .338s are now more popular among Alaskan hunters than .375s.

	(This is article appears in the December 2007 issue of GUNS & AMMO magazine, which is on sale now at your local newsstand. Click HERE for a look at the other great features and stories available in the December 2007 issue)