5 Best Cartridges and Calibers for Bison Hunting

This is about the most perfect shot you could hope to get. A standing still broad-side right into the lungs.

The American Bison is the toughest animal in North America to bring down. Many boys and men, including myself, have dreamed about hunting this magnificent legend. Here are five of the most highly recommended calibers and loads for Bison hunting.

CaliberBullet WeightApprox VelocityApprox Energy
30-06220 grain 2410 fps2837 ft/lbs
338 Win Mag225 grain2840 fps4029 ft/lbs.
375 H&H3002530 fps4263 ft/lbs.
.416 Rigby400 grains2415 fps5180 ft/lbs.
45/70 405 grains2000 fps3597 ft/lbs

The “best” calibers vary as much as the hunters using them. I’ve talked with people who prefer the high-speed Wetherby magnums, folks the think the 500 Nitro is just enough, and one old-timer who killed several with a 30/30. I’ve decided to get my information from hunting guides since they’ve seen it all.

30-06 Springfield

You may be surprised to see the 30-06 on the list. Well, don’t be. The 30-06 was the African safari gun of choice for many men from 1910 to 1940. The only difference was they didn’t use the bullets we commonly have today.

When you load up a 30-06 to full power with a 220-grain bullet, impressive things happen. A bullet like that has a lot of kinetic energy and holds on to it well too. Combine that with a nice controlled, slow expanding bullet and it will penetrate several feet through bone and flesh without a problem.

A top-end 30-06 load is generally considered the ethical minimum for Bison. In some areas, it’s the legal minimum. Trouble is, it’s not easy to find a 30-06 load with a Buller over 200-grains.

Hornady has one load, but it’s only available in Europe. Remington does sell a 220-grain Core-Lokt in 30-06 that is recommended by several Alaskans I’ve talked with. The downside to the 30-06 is that the bullet is skinny.

Taking a bison usually means making a lung shot and waiting for its lungs to fill with blood. they have huge lungs and that can take a while. Big bullets do that much quicker. In fact, some guides would prefer hunters to use a faster expanding bullet providing they actually would wait for a perfect lung shot.

338 Win Mag

Hornady makes a superb bullet in 338 Win mag for big, tough animals. It’s loaded with a 225-grain SST bullet and it’s essentially a +P version, going 200 fps faster than most others on the market. It fires a controlled expansion bullet that will devastate a bison with a decent shot.

.416 Rigby

The .416 Rigby is considered an elephant gun by many, and it’s killed many a pakederm. Given a 400-grain controlled expansion bullet, like Hornady’s DGX Bonded, it’s able to put down the biggest trophy bison on the plains.

This caliber relies on both velocity and weight to get the job done. It packs some serious power, and recoil. Honestly, most of the guides I’ve talked too don’t prefer hunters to use this caliber because most people aren’t comfortable with it and don’t shoot it well.

The Alaskan wildlife department recommends using the 30-06 as a baseline and only going up in power if you can shoot it as well as the 30-06. Most people just can’t.

375 H&H

The 375 H&H is the old standby for tough-to-kill animals under elephant size. Its only issue, and the issue with all the big bore calibers here, is that they slow down quickly. That’s part of the reason why hunting guides won’t generally let a hunter take a shot at a bison further than 200-yards.

In reality, most professional bison guides try and get within 100-yards before allowing a client to take a shot. Bison are amazing animals and the closer you get, the better shot you will take and the more effective it will be.

45/70 Government

The 45/70 government was invented to hunt buffalo. And, after the innovation of smokeless powder and better steel, it’s gotten ridiculously more effective. This is the most popular option seen on bison hunts.

As long as you aren’t using an old trapdoor style (black powder only) rifle, you can really push the limits of what your shoulder can handle with the 45/70. If you want to see what a stout 45/70 load can do, I suggest going over to Buffalo Bore Ammunition and browsing their offerings.

One thing you will notice about it is the lower velocity compared to the other options here. Velocity is bigger deal than bullet weight when it comes to adding ft/lbs. of energy. But, there’s more to the equation. his bullet uses weight and its inertia carrying ability to penetrate deep.

Old-timers often prefer a 500 grain 45/70 lead bullet going around 1600 fps. Buffalo Bore really pushes the limits with its 405-grain and 500-grain bullet. Even though they are slow they penetrate like a freight train. Their 500-grain solid is not recommended for bison though. Professional guides prefer controlled expansion bullets.

What Other Calibers are Used?

Interestingly, I’ve heard a couple of guides speak highly of an in-line 50 caliber muzzleloader. That’s almost hard to believe because a friend of mine shot one 4 times with a muzzleloader though it was on the run (an escaped farm bison) and some shots were a bit forward.

From what I can gather, the big diameter bullets work great with lung shots. Trouble is, you’d really have to be well within 100-yards because these big bullets slow down quickly and are probably going 1600 fps at best. Definitely not what I’d call ideal. Jim Shockey made that more popular.

I tend to lend an ear to the Alaskan fish and game department when it comes to caliber selection. These guys are generally very sensible on the topic in my opinion. Here are the Alaskan firearm regulations for hunting Bison.

  1. Rifle/handgun: must fire a minimum of a 175 grain bullet having a minimum of 2,800 ft/lb energy at the muzzle.
  2. Muzzleloader: muzzle-loading rifles must be .54 caliber or larger, or at least .45 caliber with a 300 grain or larger elongated slug. Further, for safety reasons, those hunting with muzzleloaders must also have within easy reach a smokeless powder rifle meeting the centerfire rifle requirements listed above.
  3. Black Powder cartridge rifles: must fire a 400 grain bullet or larger loaded with a minimum of 70 grains of black powder or equivalent (.45-70 with a 400 grain bullet or a .44-90 with a 550 grain bullet).
    Not Legal — .45-70 loaded with 55 grains of black powder, or a .45-70 with a 330 grain bullet.

By the way, Alaska fish and game has a great article on Bison shot placement. Here’s a link to it.

I’ll end with this, Every guide I’ve talked with says get within 100-yards and pop the lungs to bring a beast down. Even a mid-power rifle will do that just fine. If you hit the shoulder, you better have a solid, deep-penetrating bullet.