These two military rounds take long-distance shooting to a new level: the 338 Lapua Magnum, and the 50 BMG.
The 50 Browning Machine Gun (aka 50 BMG, .50 cal, 50 Browning, or 12.7x99mm NATO) was designed for anti-materiel applications and is the longest-serving centerfire cartridge in the U.S. military (excluding the 30-06 Springfield, which is still used during ceremonial occasions). The 338 Lapua Magnum is a relative newcomer to the long-range shooting scene, but has become a favorite of many snipers.
Let’s evaluate the 50 BMG vs. 338 Lapua to help you understand the differences between the two rounds and give you a clearer idea of which is better for your long-range shooting needs.
The key difference between 50 BMG and 338 Lapua Magnum is this: the 50 BMG is the larger cartridge, and accordingly fires a bigger, heavier bullet with more kinetic energy. Although the 338 Lapua has considerably less case capacity than the 50 BMG, both rounds share similar muzzle velocities.
Perhaps the most obvious difference between these two rounds is their size.
The 50 BMG’s enormous case capacity and projectiles come at a cost: massive recoil. The 50 BMG has significantly more recoil than the 338 Lapua. That’s a major reason why many shooters prefer the smaller 338 Lapua for more applications.
It is impossible to perform a pure apples-to-apples recoil comparison on these cartridges, as they are fired in very different firearms. That being said, we can objectively compare the rounds’ free recoil, which is a product of four factors: muzzle velocity (fps), propellant charge weight, bullet weight, and firearm weight.
For 50 BMG, we will consider the Barrett M82 semi-automatic sniper rifle, weighing a whopping 32.7 pounds. For the 338 Lapua, a McMillan TAC-338 bolt-action rifle weighing 13.0 pounds. For ammo, we will compare the military’s standard-issue 50 BMG M33 ball 660 grain FMJ (2,910 fps muzzle velocity) and Lapua’s 338 Lapua Mag 250 grain Lock Base FMJ (2,952 fps).
Given these parameters, the 50 BMG generates ~82.7 ft-lbs free recoil energy; the 338 Lapua, 36.5 ft-lbs. (To put these massive recoil quantities in perspective, an average 308 Winchester load produces ~20.0 ft-lbs of free recoil.) In no uncertain terms, the 50 BMG has more than double the recoil of the 338 Lapua Mag.
The amounts of recoil produced by the 338 and the 50 BMG are so excessive that virtually every rifle chambered for either comes with a factory-installed muzzle brake. Without it, most shooters would not be able to fire accurately.
Most shooters understand what they’re getting into when they make the decision to purchase a 50 BMG rifle. If you aren’t already experienced with it, then it would be wise to consider professional training to learn how to handle such a mighty round’s recoil.
Ballistic coefficient (BC) is a measure of how aerodynamic a bullet is and how well it resists wind drift.
The 50 BMG has some of the highest BC values among centerfire rifle cartridges, with heavier bullets exceeding 1.000 G1 BC. The 750 grain A-MAX has a G1 BC of 1.050, while the 660 grain FMJ has a BC of 0.701. In comparison, the 250 and 300 grain 338 Lapua loads compared earlier have G1 BCs of 0.625 and 0.720, respectively.
Sectional density (SD) reflects a bullet’s capacity for penetration based on its weight and diameter.
Narrower bullets typically have an advantage in SD, as they can focus more of their energy on a narrower area. However, 50 BMG bullets are so much heavier that they brute-force their way to higher SD values.
The 50 BMG 750 grain A-MAX has an SD of 0.412; the 660 grain FMJ, 0.357. In contrast, the 338 Lapua 300 grain AccuBond has an SD of 0.375, falling between the two .50 cal bullets.
Initially developed for military use as aircraft and anti-aircraft guns, the 338 Lapua Mag and 50 BMG have both been used by civilians in F-Class shooting competitions.
Since both cartridges are very niche, there are not too many practical reasons to own them (besides being able to brag to your buddies that you have one of the baddest rifles on the planet). Both are good options if you’re a competitive Extreme Long Range (ELR) match shooter or long-range big game hunter (though in most instances there are better options for hunting).
The 338 Lapua and 50 BMG are relative newcomers to the big game hunting scene. In most cases, I wouldn’t recommend using either for hunting.
There’s no question that 50 BMG ballistics are impressive. No animal on the planet can stand up to it. However, the .50 cal has several downsides for hunting.
Read the full comparison here: https://ammo.com/comparison/338-lapua-vs-50-bmg
