How to Select the Right Hunting Bullet

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Hand me a couple more bullets. We all say it, when we really mean: Hand me a couple more cartridges. We mix cartridges and calibers, too. Cartridge is the whole ball of wax: Primer, propellant, bullet, and case. Every cartridge, small to large, contains those four components.. Caliber refers to bullet diameter. Fortunately, bullet diameters are more or less standardized. We make it more complicated by rounding the numbers up and down…and sometimes we go metric. All cartridges that are nominally .270 (6.8mm) use .277-inch bullets. All 7mm cartridges use .284-inch bullets, including those called 28, .280, .284. All .30-calibers use .308-inch bullets, sometimes called .30, .308, and .300.

Cartridge Nomenclature

The complete name of the cartridge is based on a standardized and unique set of dimensions and performance characteristics. Going back 150 years, most cartridges are named by nominal bullet diameter, followed by the name of the developing manufacturer. As in .270 Winchester or .280 Remington. Often, a modifying buzzword is added, as in 7mm Remington Magnum. The word “magnum” comes from the French for an extra-large bottle of champagne. We can figure that a magnum cartridge probably has a larger case and is (usually) more powerful.

Naturally, things aren’t that simple. There are exceptions, and some go back a long way. .45-70 Government goes back to 1873, using the blackpowder convention of following caliber with weight of powder charge: .45-caliber, 70 grains of blackpowder, developed by the US government. .30-30 Winchester, introduced in 1895, used the same rule. .30 caliber, 30 grains of then-new smokeless powder. .30-06 is abbreviated from the official name: Cartridge, Caliber .30, Model of 1906. 7mm-08 Remington is a 7mm based on the .308 case necked down.

Because the word magnum was used so much it lost meaning, new cartridges often have what I call whimsical names: 6.8 Western, .350 Legend, the Creedmoor family, the PRCs (Precision Rifle Cartridges). For any cartridge, there is just one name, tied to one set of dimensions and performance characteristics. Rifles will be so roll-marked, and cartridges so headstamped. It is difficult to know exactly how cartridges are supposed to perform without studying and comparing case dimensions and ballistic data.

Bullets Doing the Hard Work

Let’s get back to bullets. In hunting, the bullet does the work. There’s a confusing array of brands, designs, shapes and weights, and all manufacturers are certain they make the best bullets. We’re going to focus on bullet weight. In the English system, we measure bullets in grains. Not like grains of sand. The grain is a unit of measure, 7000 grains to one pound. Most calibers and cartridges are offered in multiple bullet weights.

In most bullet diameters, there are multiple cartridges: For example, .270 Winchester, .270 Weatherby Magnum.270 Winchester Short Magnum; .280 Remington, 7mm Remington Magnum, 28 Nosler; .308 Winchester, .30-06, .300 Winchester Magnum. Among common hunting cartridges .270 (.277-inch bullet), 7mm (.284-inch bullet) and .30-caliber (.308-inch bullet) are popular, and are good examples because 150-grain bullets are available in all three. They are not the same. .277 is a smaller diameter, so a 150-grain .277-inch bullet must be longer than a 150-grain 7mm, and a 150-grain .30-caliber bullet is shorter yet.

This is important because if construction and impact velocity are similar, bullets that are longer and heavier-for-caliber penetrate better on game. However, it takes more pressure to push a heavier bullet down the barrel. So, in any given cartridge, the lighter bullet(s) will be faster. This means they will shoot flatter…over shorter distances. Over the long haul, bullet shape—aerodynamics—play a major role, so the race isn’t always to the swiftest bullet.

The range of bullets available in any cartridge goes back to the standardized design characteristics. These include Cartridge Overall Length (COL). Important because COL dictates the action length the cartridge will fit into. Also included in design specifications is the recommended rifling twist. Any given twist can only stabilize bullets of certain weight (actually, length). Basically, the shorter the bullet, the slower the twist. Muzzleloaders intended for round balls may have a twist as slow as one turn in 50 inches (expressed 1:50). Modern ARs intended for the new extra-long and heavy .223 bullets may have a twist as fast as 1:6.

We usually don’t need to worry about this too much; rifle manufacturers will barrel their rifles to provide accuracy with factory ammo. Usually. I have an older AR with the then-common 1:12 twist. Great for light varmint bullets of 55-grains and under, all done at about 62-grains. I have adequate accuracy to hunt deer with that bullet weight, but I can’t use heavier .223 bullets now available. These days, AR manufacturers often offer choice of barrel twist; it’s important to know what you’re going to use it for, and what twist will best stabilize the bullets you intend to use.

Driving Bullets to Perform

Bullet construction matters. A lot. So does velocity. In general, the faster the cartridge, the tougher a bullet must be to hold together. However, the simplest way to increase performance on game is to increase bullet weight. Sheer bullet mass covers a lot of sins in bullet construction.

Ol' 30 Cal

Let’s say you’re primarily a deer hunter, shooting a .308 or .30-06. America’s darling .30-caliber offers a great example. The most common .30-caliber bullets are 150, 165, or 180-grain bullets. In .308 and .30-06, 150-grain slugs are wonderful deer bullets. Chances are that’s what you use.

Now let’s say you drew an elk tag. Or you’re going to Africa, where plains game varies greatly in size. Consider adding bullet weight. Add 10 percent bullet weight and you have the 165-grain bullet; add 20 percent and you have the 180-grain bullet. It's impossible to say how much more bullet weight is needed to see a difference. It depends on bullet construction and speed, also diameter. In .30-caliber, I think 10 percent makes a difference; I see the 165-grain bullet as a great compromise between higher velocity and more consistent penetration. I know 20 percent changes the game. In .30-caliber, the 180-grain bullet is what I’ve mostly used most for elk and the general run of African plains game.

Or let’s say you’ve upgraded to a faster cartridge. I’ve hunted a lot with various magnum .30s, but rarely with 150-grain bullets. In fast cartridges I go heavier out of concern about bullet blowup at close range and full velocity.

Today’s longer, heavier “low drag” bullets change the equation, but not the concept. Going back 40 years, in both .300 Weatherby Magnum and .300 H&H, I usually loaded 200-grain bullets for larger game. That’s a one-third increase in bullet weight over the popular 150-grain .30 caliber. Today, in .300 Win Mag and .300 Wby Mag, I’m mostly shooting 200-grain ELD-X. They can’t start as fast as lighter bullets, but aerodynamics let them catch up downrange.

That 7mm Speed

The math isn’t as convenient with .270 or 7mm, but the same principle applies, with several ascending weights of popular bullets. In 7mm, the most common weights are 140, 150, 160-something, and 175-grain, with “low drag” bullets even heavier. In various 7mm cartridges, I’m loading bullets from 140 t0 195-grains. That’s up to a 46 percent increase in bullet weight.

I think of 140 and 150-grain 7mm bullets as deer bullets. In slower cartridges—7x57 and 7mm-08—I mostly shoot 140-grain bullets At their moderate velocities, bullet performance is routinely excellent. In faster 7mms, such as the 7mm Remington Magnum, I usually stepped up to medium-weight bullets, 160 to 165-grains. Again, this is out of concern about bullet blowup with light, bullets at full velocity. In the several 7mm Rem Mags I’ve owned, I rarely shot 140-grain bullets and almost never the 175-grain heavyweight. With the medium weights I never had problems with elk-sized game.

Most American 7mm cartridges have been barreled with 1:9 or 1:9.5 twist, which pretty much maxes out with 175-grain bullets. My newest baby is a 7 PRC with 1:8 twist, shooting bullets up to 195-grains. On one level, it’s silly. I’m not a long-range competitor, nor an extreme-range shooter on game. The heavy bullets are slower than lighter bullets and kick more. At some distance, they will pass the lighter, faster bullets…farther out than I’m likely to shoot. My only defense: I’m thinking of the 7 PRC as an elk rifle, not a deer rifle.

Classic .270

The .277 bullet diameter is a different deal. With 1:10 twist since 1925, traditional .270s (Winchester, Weatherby Magnum, WSM) are limited to 150-grain bullets with moderate aerodynamics. Primary bullet choices have been 130, 140, and 150-grains. Most popular is the 130-grain bullet, excellent for deer-sized game. Being sort of a heavy-bullet guy, for larger deer I often stepped up to 140-grains. That’s just a 7.7 percent increase in bullet weight. I’m not sure if that increase made a difference or just made me feel better. For elk, I stepped up to 150-grains, which is a 13.3 percent increase. It makes a difference.

“New” .270s (27 Nosler and 6.8 Western) have faster twists and brought with them .277 bullets up to 175-grains. That’s a 27 percent increase. Big difference. With similar velocities and now like bullet weights, these fast .270s are on par with 7mm magnums…and kick the same.

Tougher bullets lose less weight during penetration and can be lighter for similar performance. Homogenous-alloy bullets are very tough, although they generally don’t expand as much as lead-core bullets. Unless petals break off (which happens), they retain most of their original weight. The copper-alloy bullets are deep-penetrating bullets, usually exiting on broadside shots. Some hunters love them; others prefer the larger wound channels of lead-core bullets. Because they retain most of their weight during penetration, you can go a bit lighter with copper-alloy bullets and still be certain of adequate penetration. 

American rifle shooters tend to obsess on accuracy and velocity.  In hunting, bullet performance is everything. Ignore seductive velocity and avoid lighter bullets, unless of known tough construction. On larger animals, avoid light bullets anyway, and don’t hunt with match bullets, regardless of weight. They are designed for accuracy, not terminal performance, and tend to be inconsistent on game As for accuracy, the vital zone of game animals is a large target. Accuracy yields confidence and that’s good, but for hunting ammo, compromise on group size in favor of bullet performance. Which, regardless of all else, you will almost always get by simply increasing bullet weight. 

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