The Boom in Big Bores

Here's what's driving the monster-caliber craze.

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If you’ve been hanging around gun shops recently and overhearing the conversations of the cognoscenti, you might well get the notion that someone turned the clock back a hundred years or so. After a century of determined design and development of speedier cartridges and racier rifles to fire them, there is now a resurgence of interest in cartridges that were, or might have been, right at home on the pages of an 1890 gun catalog.

We shooters and hunters tend to be romantically inclined and give up our traditions at about the same pace as stones rolling uphill. This explains why we suffer periodic fits of teary-eyed nostalgia and dust off timeworn classics like the .22 Hornet, .30/40 Krag and .45/70. Such groundswells of interest have tended to subside after a year or so and remain dormant until the next high tide of nostalgia. Which is why, only a couple of years ago, I would have predicted that the boom in big-bore cartridges and rifles was only a slight and temporary detour in our quest for ever-higher velocities of relatively small-caliber bullets.

However, now I’m not so sure such a prediction would be on target, because there is a sizable and growing cadre of hunters who are stoutly convinced that big-bore cartridges are better and surer killers of big-game animals. And I, for one, am not the least bit inclined to disagree, even though I don’t consider myself a big-bore aficionado. If you’ve missed out on this trend all you need to do to catch up is browse the Internet for hunting and firearms Web sites and you will find chat rooms filled with talk of big- caliber hunting rifles. But what exactly is a big-bore rifle and what are the division markers between small bores, medium bores and the big stuff?

How Big Is Big?
As a rule of thumb you can figure that the small-bore class includes any caliber less than 8mm (.32 caliber) or thereabouts; the mediums range from .33 to .375 caliber (the .338 Winchester Magnum and .375 H&H; Magnum being examples of both ends); and above that come the big boomers.

The group of big bores we’re talking about here does not include the heavy calibers used primarily for dangerous African game, such as the .470 Nitro, but rather somewhat less gigantic rounds developed and intended for North American game ranging from whitetails to grizzlies. Think of a bullet about the size of your thumb thumping a moose and you get the idea-along with a whiff of the romance of hunting the deep woods with a big-bore rifle.

For mathematically inclined students of ballistic charts, the performance of big boomers doesn’t seem to add up. Consider, for example, why the .444 Marlin, a bona fide big boomer with a 240-grain, .44-caliber bullet, yields only 2,942 foot-pounds (ft.-lb.) of energy at the muzzle, whereas, say, a comparative pip-squeak like the 7mm Remington Magnum gets 3,133 ft.-lb. at the muzzle with a bullet of little more than half the size and weight. It’s because the method with which we usually calculate bullet energy is heavily tilted in favor of velocity. Double a bullet’s weight and you only double its energy if velocity remains the same. But double its velocity and energy increases fourfold!

This has been a bone of contention for as long as hunters have argued over cartridge performance with big-bore fans, who often use other methods of calculating bullet effectiveness, claiming that energy figures on paper are a poor substitute for the big hole and deep penetration of a fat, heavy bullet. “Brush bucking” also enters the debate from time to time, but let’s open that Pandora’s box another day.

Hunting Hardware
Big cartridges of the American variety go hand in hand with lever-action rifles and, to a lesser degree, single-shots. For several years a couple of mainstays have been various models of Marlin lever rifles in .444 Marlin and .45/70. More recently Marlin sweetened the kitty with its highly popur “Guide Gun” series of lever guns, the essence of which is heavy-caliber, carbine-length rifles of the sort a savvy wilderness guide would carry in case an occasion should arise in which he’d be called on to rescue himself or a client from the mangling grasp of a grizzly. Hunters’ imaginations take wing at such scenarios, so the Guide Guns were instant classics.

Strangely, a similar attempt by Winchester back in the late ’70s with its M-94 Big Bore never took hold. It was chambered for the .375 Winchester round, which was loaded with 200- and 250-grain bullets, but the rifles never sold well and were discontinued after a decade. Probably the .375 Win. was too far ahead of the current big-bore craze, or just not big enough. These days Winchester is more in step with its Model 94 “Timber Carbine,” which sports an 18-inch barrel in .444 Marlin caliber.

What really blew the socks off big-bore fans a couple of years ago was the joint announcement by Hornady and Marlin that they had collaborated on a new round-the .450 Marlin. With a 350-grain, .45-caliber bullet with 3,427 ft.-lb. at the muzzle, this was manna for the big-bore crowd and had the added titillation of having a magnum-style belted case. (Outdoor Life Editor-in-Chief Todd Smith used an early edition of the .450 Marlin to take a big bull moose in Alaska, and told of his adventure in the April 2001 issue.)

The .45/70 Returns
Another reason for the current popularity of thumb-size bullets is recurring interest in the .45/70. This old warhorse, which has been around for over a century and a quarter and has outlasted dozens of newer calibers, refuses to die and constantly wins new fans. Such popularity is due no doubt to some excellent rifles recently introduced in that caliber-Marlin’s Model 1895 “Guide Gun” is one, and Ruger’s Number One single-shot in .45/70 has remained in demand for years. Also, there has been a steady upgrade in .45/70 factory ammunition, such as Winchester’s move to load it in its top-of-the-line Supreme category with a 300-grain Partition Gold bullet.

The .45/70 has been a long-standing favorite of handloaders who cast and load lead bullets. Bullet casting is the real nitty-gritty of handloading, and in big bores like the .45/70, good cast bullets will equal, and often exceed, the accuracy of jacketed bullets. With strong modern rifles like the Marlin and Ruger, there’s no problem loading 400-grain bullets, cast or jacketed, close on to 2,000 feet per second (fps), which is a solid wallop for any game animal that walks this continent. Several years back I did a lot of hunting with a Ruger Number One loaded with bullets I’d cast from linotype, which is a lead alloy hardened with tin and antimony. When recovered from a couple of elk, these hardened bullets were semi-mushroomed after deep penetration. Similar experiences by thousands of other handloaders of cast bullets no doubt have added to a firm belief in the effectiveness of big-bore cartridges. Marlin did cast-bullet shooters a big favor when it abandoned Micro-Groove rifling (which doesn’t like cast bullets) in its big-bore rifles and switched to cast-bullet-friendly, wide-groove, cut rifling.

Two New Sports
I’m only speculating, but I think another cause of the boom in big bores has shooting sports: Cowboy Action Shooting and Black Powder Cartridge Silhouette. The rules of Black Powder Cartridge Silhouette shooting call for rifles, or reproductions of such rifles, dating back to buffalo hunting times. Players shoot at steel silhouette targets at distances out to 500 meters. It’s only a micro-step from thumping a steel ram at 500 meters with a thundering Sharps rifle (waiting lists for good Sharps reproductions are measured in years) to wanting to do the same to a live bull elk.

The same is true for the Long-Range Rifle events in Cowboy Action Shooting, which may include targets at 200, 300 or even 500 yards. Calibers of choice include the .45/70 and .40/60 Marlin, among others. All of which gladdens the hearts of big-bore hunters everywhere.

As a final note-call it a warning-the big bores can be addictive, so beware. Who knows, there may be a .45/70 or even .45/120 Sharps somewhere in your future. been the timely emergence of two basically non-hunting yards. Calibers of choice include the .45/70 and .40/60 Marlin, among others. All of which gladdens the hearts of big-bore hunters everywhere.

As a final note-call it a warning-the big bores can be addictive, so beware. Who knows, there may be a .45/70 or even .45/120 Sharps somewhere in your future. been the timely emergence of two basically non-hunting