The Best Cartridges For Hunting Big Bears

October 6, 2023. The day before brown bear season on the Alaskan Peninsula. In the wee hours, a few hunters gathered at the Anchorage airport. Later, a concentration formed at Lake Clark Air, headed southwest to jumping off points down the massive Peninsula. A couple dozen hopeful hunters headed to big bear country. Always fascinated by rifle choices, I asked around. A few .338 Winchester Magnums, one .338 Lapua, one .340 Weatherby. Lots of .375s, both H&H and Ruger, a smattering of .416s. Virginian Robert Rush was carrying a .300 RUM. “The biggest rifle I own.”

All bears are tough, and the bigger they are, the harder they fall. Brown, grizzly and polar bears taken by hunters are almost never weighed, so it’s hard to say how big they get. References suggest 1,500 pounds for a large coastal brown bear, likewise with the largest polar bears. The largest bears I’ve seen taken seem about the same size as a normal southern Cape buffalo. A difference: Almost all buffalo bulls run from 1,400 to 1,600 pounds. With bears, there’s a big delta between fall weights and spring weights just out of hibernation. Interior grizzlies are unlikely to meet the magical “ten-feet, ¾-ton” mark, and coastal brown and polar bears are shootable and desirable well short of that mark. It doesn’t matter; a 900 or 1,000-pound bear is a formidable and dangerous beast, the world’s largest predator. It’s downright foolish to tackle a big bear without a very adequate cartridge firing a good bullet.

ONLY GUIDES KNOW

The difficulty lies in knowing exactly what that means. For most of us, it’s just clinical discussion; only experienced guides can acquire extensive experience with our biggest bruins. In the 1930s, Alaska allowed up to four brown/grizzly bears on a license. After WWII, most areas were reduced to two bears. Alaska still has some two-bear units, but more commonly the limit today is one.

With less opportunity and skyrocketing costs for non-Alaskans, hunting a big bear is often a once-in-a-lifetime experience. This applies to me, too. I’ve been doing this a long time, starting when costs were laughable compared to today. I think I have as much experience with big bears as any living gun writer. That’s still not much. I pay attention to what the guides carry.

Considering yesteryear’s high bag limit—and available choices back when—it’s likely the .30-06 (with 220-grain bullets) accounted for as many big bears as any other single cartridge. However, as more powerful choices became available, guides and serious Alaskan hunters learned and upgraded. In 1936, Winchester included the .375 H&H as an initial chambering in the Model 70.

The .375 had long proven itself on the biggest bears, but the M70 was the first American factory rifle to offer this level of power. The .375 H&H quickly became a standard choice. It wasn’t the only option. Also introduced in 1936, the lever-action Winchester M71 in .348 had a following, but some found its 250-grain bullet at 2,350 fps lacking on the biggest bears. Among them was Harold Johnson on the Kenai Peninsula. He necked the .348 up to .458 and rebarreled the M71. His .450 Alaskan propelled a 400-grain bullet at about 2,000 fps. Quite a few M71s were so converted—I had one for a time—but scopes were coming into common use. The top-eject M71 defied scope mounting. A bolt-action .375 H&H remained dominant for big bears.

Some went bigger. Don Johnson and Ron Hayes, both doing a lot of polar bear hunting (in addition to grizzlies and brown bears) went to the .458 Win. Mag. after it came out in ’56. Famous brown bear guide Andy Runyan used a double .500 Nitro Express, and Harmon “Bud” Helmericks had a .470 double. Old friend Jake Jacobsen has perhaps the most unusual gun ever used to dig a big bear out of alders: A three-barreled drilling with two 12-gauge barrels on top and a 9.3x74R barrel on the bottom.

DIFFERENT PURPOSES

Experienced guides know what works—for them. Before we read too much into that, it’s important to understand that a guide’s purpose is different from yours and mine. A good guide’s intention is to never shoot until essential, as a matter of safety or to prevent the loss of a wounded animal. When it becomes necessary the guide’s shot will usually be close. He (or she) may carry a more powerful rifle than absolutely necessary—just in case. Master Guide Alisha “Mutts” Rosenbruch-Decker and her husband are among numerous Alaskan guides who have bypassed the .375 and upgraded to .416.

Dave Leonard, also a Master Guide, has been my primary mentor in Alaskan hunting for 30 years. Leonard is a staunch .375 guy, typically carrying a well-battered left-hand Remington M700 .375 H&H. Recently, he got a .450-3 ¼” double with an Aimpoint.

I was brown bear hunting on the Peninsula with Leonard’s Mountain Monarchs of Alaska outfit, guided by Australian Pete Mayall, also left-handed. Pete’s backup rifle was a typical modern “guide’s rifle,” an inexpensive left-hand Ruger M77 Hawkeye in .375 Ruger. It had a tough laminate stock, modified only with Cerrakote finish and detachable scope.

We were stalking a big boar we felt certain had gone into dense alders. We couldn’t find the bear, but we had tense moments in thick stuff in wind-driven rain. Before we went in, I noted that Pete stopped and pulled the scope off his rifle.

This is a difference between a guide’s choice and yours or mine. Nobody makes “long” shots on large, dangerous animals like an Alaskan brown bear. You get as close as you can, but that often means a 200-yard shot. Between big country and fickle weather, you can’t expect more than one opportunity. Maybe it will be up close and personal. Turn your scope all the way down, but choose a rifle, cartridge and sights that will let you take and make the shot, whatever cards you are dealt.

There’s also a difference between the rifle a guide might carry, and a firearm carried for last-ditch personal defense against bears. For the latter, many rely on bear spray alone and work at steering clear. Others carry large handguns or short slug-loaded shotguns. Popular today are the big, .45-70 lever-actions we call “guide guns,” featuring rust-proofed metal with fast ghost-ring aperture sights. With heavy loads in strong, modern actions the .45-70 is plenty adequate, but it’s a short-range affair with arcing trajectory (much like the old .450 Alaskan).

The thing is, guiding bears and defending oneself against bears aren’t the same as hunting for a big bear. There’s one chance with much at stake, the shot depending on what the hunting Gods offer. This year, young friend and fine editor David Faubion had a chance to go brown bear hunting. He asked me about taking a .45-70 guide gun. I recommended against it, suggesting a scoped .338 or .375. He chose a .338. Faubion got one opportunity late in his hunt and dropped a nice bear—a bit too far for a .45-70 to be certain. He thanked me for good advice. I’ve seen just one Alaskan guide carrying a .45-70 lever-action. He was in his first season then, and has now switched to a scoped bolt-action.

.338 OR .375

Using handloaded 220-grain bullets, Robert Rush took a nice brown bear with his .300 RUM. A hunter in our fall ’23 camp also took a nice bear with his .300 RUM. With the great bullets we have today, faster .30-calibers will do the job. Obviously, the .416s and larger are plenty of gun, and the .416s shoot flat enough. Another hunter in our ’23 camp, all the way from Austria, flattened a nice bear with a 400-grain Swift A-Frame from a .416 Rem. Mag. Spectacular. With good, heavy bullets, fast 8mms, .35s and 9.3mms (.366-inch) would certainly work and are preferable to .30s. However, in fast (and thus versatile) cartridges, these bullet diameters are uncommon in the U.S. So, I think the primary choices for hunting our biggest bears boil down to the several .338 and .375-caliber cartridges.

Elmer Keith had been wildcatting fast .33s for years. Winchester answered the mail in 1958 with their .338 Win. Mag., in a version of the M70 called the “Alaskan." Winchester’s engineers believed the cartridge would be plenty adequate for the biggest bears. Elmer Keith believed in heavy bullets and got them. The 250-grain .338 bullet has higher Sectional Density (SD) than the 300-grain .375, so will penetrate at least as well. Winchester also had an early 300-grain factory load for the .338.

I think both Keith and Winchester were right, but the vote isn’t unanimous. A few years ago, Alisha Rosenbruch-Decker guided Donna to her big brownie. We showed up with Donna armed with a Proof Research .338. Alisha told us flatly: “We like a .375 minimum for brown bear.” Well, too late to do anything about it. Quartering slightly away, Donna put one 225-grain InterBond behind the on-shoulder and into the off-shoulder. The bear took one step and went straight down. To be certain, she fired one follow-up shot. It was unnecessary.

Dave Leonard’s outfit likes a .338 minimum for his big Peninsula bears. The .338 Win. Mag. is the baseline, firing a 250-grain bullet at something over 2,600 fps. Flat enough for any sensible shot and, in my view, plenty of power and penetration.

Nobody today has as much experience with polar bears as Shane Black of Canada North. He recommends .338s, .375s and .416s. Usually the shot is close, but there can be the necessity to stop a bear short of open leads or impassable pressure ridges, so a scoped rifle is best. In modern times, it’s unlikely any single rifle has accounted for as many polar bears as the Blaser in .338 Win. Mag. Shane keeps in camp for hunters who prefer not to bring their own. He feels the .338 is plenty of gun, well-proven on big white bears.

There are faster .33s, including .340 Wby. Mag, .338 RUM, and the big Lapua. They shoot flatter and deliver more energy; I’ve taken both brown and grizzly bears with the .340. It’s awesome, but above .338 Win. Mag., recoil increases sharply.

Let’s turn to the .375. From .375 H&H up, it’s one of the world’s most versatile calibers. It is also a jack-of-all-trades and master of few. Adequate for the largest game, but not dramatic on pachyderms. Needlessly powerful for smaller game, not as flat as one might like for mountain game. The .375 is perfect for eland, lion and the biggest bears.

The .375 H&H is the gold standard with a 300-grain bullet at about 2,530 fps. I shot my big Alaskan brown bear with a Sako .375 H&H and 300-grain bullets. Great choice then, great choice today. Except for availability in makes and models, no real reason to look further. Except that, in standard-length actions and with a bit more velocity, the .375 Ruger is probably the better cartridge. With today’s bullets, I think it’s no longer essential to use the 300-grain pill. I shot my polar bear with a Mossberg .375 Ruger using fast 250-grain GMX. Big bears don’t give up easily…and you don’t take chances. I think the first shot was fine, but I shot the bear three times, all three bullets exiting.

As with the .338, there are faster .375s: .375 Wby Mag and RUM, and the big .378 Wby. Mag. All are awesome big bear medicine. However, the flatter trajectories aren’t important for shots on bears, their greater power isn’t required, and recoil gets painful.

THE TOUGH CHOICE

I took my giant brown bear on the Alaskan Peninsula forty years ago. It was so big I’ve known ever since I couldn’t beat him. In the 90s, I hunted a few times in southeast Alaska. Mostly seeking a glacier bear, I didn’t get a brown bear. In the early 2000s, I went on several hunts in northern Alaska, and finally took a big Arctic grizzly. In recent years I’ve had an irresistible urge to have one more experience with a big Alaskan brown bear.

The Alaskan Peninsula is only hunted odd falls and even springs. So, this final encounter was long set for fall ’23. Unusually, I had a tough time deciding what rifle to take. I have big guns—in multiple action types—and I like to use them. Author Robert Ruark used his famous Westley Richards .470 to take his Alaskan brown bear. I have long thought it would be cool to take a big bear with a double.

For this hunt, I was almost firm on my Heym .450/.400. Open sights are out of the question for my eyes today, but this double wears an Aimpoint. I used an Aimpoint for my polar bear.

There are other considerations. Although chances are slim, in the fall, both wolf and wolverine are open. The more I thought about it, I realized I’d kick myself forever if I had a chance and had chosen a rifle that lacked enough reach. Also, there’s bound to be rain. No way to keep water and salt air out of a double’s action. It got me thinking what Andy Runyan’s double .500 must have looked like after years of Alaskan use.

I chickened out and hedged my bet: We took Dave Leonard’s Sabatti .450 double into spike camp. Also mounted with Aimpoint, Dave bought the rifle from me, so I know it. We drew 13 typical peninsula days of intermittent wind and rain, the Bering Sea in sight over the last ridge. Dave’s double stayed snug and dry in my tent.

I have scoped Ruger No. 1s in .375 and .450/.400, but these were only passing thoughts. Same problem of keeping rust out of the enclosed action. Plus, big bears go down hard. Pure one-shot kills are unusual, and reloading a single-shot is complicated by cold, wet hands. I defaulted to a scoped bolt-action, which has been the standard big-bear solution for generations.

It could have been a .375. Instead, I put a .338 Win. Mag. barrel on my Blaser R8. I shot a European brown bear with it some years ago, remembering how fast the straight-pull action was. This barrel happens to be dramatically accurate with 250-grain Nosler Partitions. I recalled how well that great old bullet worked on both a huge Kamchatka brown bear and a B.C. grizzly, both from a .340 Wby. Mag.

Using a Leupold VX6 2-12X, I figured I was properly armed for a monster bear—and equally ready for a lucky encounter with a wolf or wolverine. Unfortunately, I can’t end this story the way I’d hoped to. Despite tough weather, we had three sightings of a very big bear, and three stalks that ended in vanishing acts and no opportunities. Sadly, this is a reality of big bear hunting: Regardless of cost and effort, success is far from certain. All the more reason to carry not just enough gun, but the right gun. Not just for the shot you hope for, but the shot you might get.

I still want one more encounter with a big bear while I can still do it. I intend to try again in spring ’24. Maybe that same big bear will be in the same drainage. Maybe I’ll carry the same rifle, maybe not, but I’m pretty sure I’ll stick with a .338 for what will likely be my last big bear.

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