There are many choices for magnum long-range cartridges, but the two commonly compared are the .300 Winchester Magnum and the .338 Lapua. This is understandable, as each has been around for decades and has seen military service by some of the most famous snipers of their time. Before pulling the trigger on an expensive rifle chambered in one of these cartridges, it pays to know the advantages and disadvantages of each. Let’s take an in-depth look at each.
.300 Winchester Magnum
.300 wins. Mag. And its story began in 1963, when America was in the throes of its .30-caliber obsession. For centuries, we considered this to be the ideal bullet diameter and that making a better long-range round involved little more than running it from a Magnum case. The early .30-caliber Magnum offered flatter trajectories and more energy downrange – something that hunters believed increased their killing power. Inspired by the greatness of Roy Weatherby, Winchester used the same .375 H&H case to create its high-velocity .30 caliber creation as it did for the .338 Win. Mag.
When fitted into a standard long-action receiver the new cartridge would push bullets weighing 150 to 220 grains faster than most offerings at the time. It hit the scene intended to attract hunters, as the 150-grain load gave them a flatter trajectory than cartridges like the .308 Win. or .30-06 Springfield, and the 180-grain load provided more energy downrange. However, since .30-caliber Match bullets were already being used in competition, they soon gained interest in the long-range competition community and, eventually, military service. Cartridges like the MK 248 Mod 1, paired with the M24 sniper rifle, extend the range of our shooters without adding substantial recoil or signature. However, it is worth noting that this load is considered overstress under SAAMI standards.
.300 Winchester Magnum Specifications
- Basic case: .375 H&H
- Case Capacity: 92 grains H2O
- Shoulder angle: 25 degrees
- Maximum coal: 3.340 inches
- Ferrule Twist Rate: 1:10 Inch
- Bullet Weight: 150 to 200 grains (normal)
- Powder: medium to slow – Verget to Staball HD
Inside the .300 Winchester Magnum
A look under the hood helps us understand where each cartridge comes into its own, as well as why they sometimes overlap. .300 wins. Mag. It was designed with standard long actions in mind, as its creators wanted it to be a plug-and-play option for rifle manufacturers. Most of the work was simply chambering a 1:10 twist .30-caliber barrel and using a Magnum (.540”) bolt face.
With a water capacity of approximately 92 grains, there is room for enough propellant to fire 150-grain bullets at 3,200 fps. On the other end of the spectrum, we can expect the 200-grainer to leave the muzzle at a respectable 2,800-plus fps. Any load yields approximately 3,400 foot-pounds of muzzle energy.
This cartridge really has a lot going for it, but it does have some outdated features – particularly its belted case. Over the years, we have found that it is not necessary to withstand high pressure, and headspacing the belt reduces stability and accuracy. To understand the problem, imagine holding a pencil upright with an eraser, then you’ll understand why the industry essentially abandoned this case design. Luckily for the .300 win. Mag., when chambered with tight tolerances, it is possible to set the headspace 25-degrees off shoulder – which is sharper than previous cartridges such as the .30/06 and .300 H&H Magnum.
.338 Lapua Magnum
The .338 Lapua Magnum was born out of a need for a long-range anti-materiel rifle round in the 1980s. Cartridges such as the 7.62×51 were not up to the task, and using the .50 BMG required a crew-served weapon at the time. Research Armament Industries worked with several companies to develop a solution based on the .416 Rigby case, but encountered compression problems. Nammo Lapua Oy or, as it is more simply known, Lapua, got the cartridge over the finish line and what we now know as .338 Lapua Magnum.
The final case design holds approximately 115 grains of water. This leaves enough propellant space to propel 230-grain bullets past 3,000 fps and 300-grain projectiles to about 2,700 fps. It produces a respective 4,995 ft./lbs and 4,855 ft./lbs of muzzle energy. The 250-grain load found international service almost immediately, with many other countries adopting or creating rifles to follow suit.
Like almost every other military cartridge, the .338 Lapua Magnum found civilian support. Its use in video game lore and the global war on terrorism is largely responsible for its popularity. Primarily a target round, most users turn to it for activities over 1,000 yards – usually when the “mile shot” is on the table. Its initial 250-grain loading is still the most popular, but the market includes options as light as 230 grains and as heavy as 300 grains, with the latter comfortably taking the second most popular spot.
Today, as long-range hunting has become more prevalent, some people are taking their .338 into the field when they need to send heavy bullets over long distances. Therefore, most ammo manufacturers offer at least one hunting-specific load, and there are even some lightweight factory rifles available for slinging them.
.338 Lapua Magnum Specifications
- Basic case: .416 Rigby
- Case Capacity: 115 grains H2O
- Shoulder angle: 20 degrees
- Maximum coal: 3.681 inches
- Ferrule Twist Rate: 1:10 Inch
- Bullet Weight: 200 to 300 grains (normal)
- Powder: Slow – from H4350 to US869
front lines first
The .338 Lapua Mag was not designed with the civilian market in mind, so little thought was given to fitting it into commercially available guns. For that purpose, most manufacturers turn to a magnum action when building a rifle to chamber it, or, at the very least, a heavily modified standard long action. The .416-based cartridge also requires a .590-inch bolt face, which is larger than the .532-inch bolt face used for the standard Magnum.
There appears to be no comparison between the two in terms of overall downrange energy, but that’s only part of the story. Performance of the .338 Lapua Mag. Comes at a cost. Feeding .338 LM often costs $6 per round – or more for match-grade fodder. Also, the .338 produces more felt recoil, so if all things are equal, the Lapua will hit you harder than the Winchester. The nice thing is that it does all this without a belt, simplifying the design and making it more inherently accurate with standard chambers.
turn off dop
So, if they are both used for ultra-long range shooting, how do the cartridges compare? Let’s take a look at the .300’s 200- and 220-grain loads and Lapua’s 250- and 300-grain offerings. The charts below show cartridges fired with a full value 10 MPH wind on a 59-degree day at sea level. 300 to win. Mag., I chose the Berger Hybrid Target for the 200-grain (.616 G1) and the Sierra MatchKing for the 220-grain load (.629 G1). As far as the .338 Lapua is concerned, I went with a Hornady BTHP for the 250-grain load (.670 G1) and a Lapua Scenario for the 300-grain load (.736 G1). Velocities were obtained from factory specifications or, where necessary, from reported maximum safe handloading data.
As you can see, all four of them keep pace with each other through the air at a distance of 500 yards, and the fall is very close. This continues for 1,000 yards. However, when we look at 1,500-yard data, the two differ. Both .300 wins. Mag. Loads have become transonic by now, but the .338 Lapua loads are still supersonic. At this point, the .338 load has experienced approximately 12 and 32 inches less airflow than the .300 Win. Mag load. This is considerable, considering how much wind conditions can change along that flight path. Furthermore, at 1,500 yards, the .338 Lapua 300-grain load delivers nearly twice the energy of the .300 Win. Mag.
savings in press
Both of these precision cartridges are likely to be reloaded by serious shooters. The good news is that both will fit in a standard press; If you’re already setup, you’ll only need the dies and components. Likewise, they use many of the same powders. For straight-line comparison, I’ll use Hodgdon’s H1000, as seen in Hornady’s 12th Versions, both for .300 Win. Mag. Data with 200-grain bullets and .338 Lapua Mag Data with 300. To pursue victory. Mag. At maximum, this will take about 76 grains of propellant. It takes 89 grains or about 20 percent more to redline the .338. Given the expense of the powder, one must ask whether it needs the extra reach. Similarly, .338″ bullets can cost twice as much as .308. While you can cut costs by reloading both, the .300 Win. Mag. is definitely the more affordable option.
final thoughts
So, who should buy which one? Well, you’ll get more hunting ammo and rifles for the .300 Win. Mag., and more target guns and ammo for the .338 LM, but there is also a lot of overlap. Both are about equal in stopping wind at 1,000 yards, so there isn’t much benefit in stepping up to a .338 if you already have a .300. If all your shooting is within 1,000 yards, win. Mag. Is more intelligent. If you’re planning to focus on ranges up to a mile, and you’re limited to factory options, the Lapua Mag. Your speed is going to be higher. However, it is worth noting that almost no serious ELR competitors are using it anymore, yet the custom .300 Win. Mags are still very common. This is because many people feel that a quality match chambered .300 offers more balanced performance with less recoil – something that can certainly be a factor during an ELR match. The answer really depends on how far you plan to shoot, how much luggage you want to carry, and how much you are willing to spend.
When .300 wins. Mag. is the best option
- When most shots are within 1,500 yards
- When factory rifle availability is important
- When hunting will be your primary use.
When the .338 Lapua is the best choice
- When you plan on shooting out to 1,500 yards and beyond.
- When you are planning to purchase a custom or semi-custom rifle.
- When you can tamper with ELR.
