Top Three Calibers for Grizzly Bear in Alaska

Grizzly bears are the most formidable game animal in North America. A mature boar can weigh 800+ pounds, is covered in dense muscle and heavy bone, and has a survival instinct that can turn a poorly placed shot into a life-threatening situation. Caliber selection is not academic here — it’s a safety decision. Here are the three best options.

.338 Winchester Magnum — The Alaskan Standard

The .338 Win Mag has become the default grizzly caliber in Alaska, and for good reason. It delivers the perfect balance of power, shootability, and versatility.

With 225-250 grain premium bullets, the .338 generates 4,000+ ft-lbs of muzzle energy and maintains killing power well beyond any distance you should be shooting at a grizzly. The bullets are heavy enough to penetrate through heavy shoulder bone and reach vitals on quartering shots, which is critical on an animal this large.

The recoil is stout but manageable for most experienced shooters. It’s not pleasant in a lightweight mountain rifle, but it’s a caliber you can practice with and shoot accurately — which matters far more than raw foot-pounds on paper.

Best for: The hunter who wants one rifle that handles grizzly, moose, caribou, and everything else Alaska throws at you.

.375 H&H Magnum — The Classic Dangerous Game Round

The .375 H&H has been the worldwide standard for dangerous game since 1912, and it remains the benchmark against which everything else is measured.

With 270-300 grain bullets, the .375 delivers devastating penetration. It’s the minimum legal caliber for dangerous game in most African countries, and it’s more than adequate for the biggest grizzlies in Alaska. The cartridge is known for deep, straight-line penetration — exactly what you need when a bear is coming at you and the shot angle is less than ideal.

The recoil is significant — more than most hunters practice with regularly. If you’re going to carry a .375, put serious time on the range with full-power loads. Flinching with a .375 at a charging grizzly is a scenario nobody wants.

Best for: The hunter who prioritizes maximum stopping power and penetration insurance, and who practices enough to handle the recoil under pressure.

.300 Winchester Magnum — The Long-Range Option

The .300 Win Mag is the lightest caliber on this list, and some Alaskan guides will raise an eyebrow if you show up with one. But with proper bullets and good shot placement, it has killed thousands of grizzlies.

The advantage of the .300 is versatility and shootability. It’s a caliber most hunters already own, shoot regularly, and are accurate with. The flatter trajectory gives you more options at distance — which matters in the open alpine and coastal terrain where many Alaskan grizzly hunts take place.

The caveat is bullet selection. Standard hunting bullets designed for deer and elk may not penetrate adequately on a grizzly’s heavy bone structure. Run premium, bonded or monolithic bullets — Barnes TSX, Nosler Partition, Federal Trophy Bonded, Swift A-Frame — in 180-200 grain weights. These bullets hold together on impact and drive deep.

Best for: The hunter who already shoots a .300 Win Mag well and wants to use a familiar rifle rather than buying something new.

Shot Placement and Premium Bullets

Caliber selection matters, but it’s second to two things:

Shot placement. A .375 through the guts is worse than a .300 through the lungs. Know the anatomy, wait for a broadside or slightly quartering-away angle, and put the bullet through both lungs. On a grizzly, the front shoulder shot is also an option with heavy calibers — it breaks the shoulder, anchors the bear, and the bullet reaches the vitals.

Premium bullets. This is not the hunt for bargain ammunition. Use controlled-expansion or monolithic bullets designed for deep penetration on heavy game. The bullet has to hold together through thick hide, dense muscle, and heavy bone to reach the vitals. A cup-and-core bullet that fragments on the shoulder is a wounded bear in the alders — and that’s a nightmare for everyone involved.

Choose your caliber, load it with the best bullets available, practice until you can shoot it accurately from field positions, and put the shot where it counts. That’s the formula for a clean, safe grizzly hunt.