458 SOCOM vs 50 Beowulf

So, you decided you can’t live without a big-bore AR, but you have a dilemma. Should you go with the 458 SOCOM or the 50 Beowulf? While they are both very potent cartridges for the AR platform, they differ in many respects. In this article, we will review these differences to help make your decision easier.

Physical Attributes

Stood beside each other, you will notice plenty of differences between the 458 SOCOM and the 50 Beowulf. Perhaps the first difference you’ll notice is that the 458 SOCOM has a bottleneck design, whereas the 50 Beowulf is a straight-wall case.

Due to their geometries, bottleneck cartridges typically feed more reliably than straight-walled cartridges. Although neither cartridge is immune to feeding issues, the 458 SOCOM is much less finicky than the 50 Beowulf, especially when fired from standard AR-15 magazines. In fact, the 50 Beowulf often requires modifications or even proprietary magazines to function reliably.

Looking at the top of each case, you will notice a rather large difference in the diameters of each projectile. As the names suggest, the 458 SOCOM uses 0.458-inch diameter bullets, whereas the 50 Beowulf uses 0.500-inch diameter bullets. This equates to an increase in diameter of just over 9%, which is relatively substantial.

Although a wider bullet diameter generally equates to heavier projectile options, this is not the case when comparing the 50 Beowulf and the 458 SOCOM. You may have noticed the difference in height between the case lengths of each cartridge, which contributes to bullet selection. At 1.65 inches in length (nominally), a 50 Beowulf case is 75-thousandths of an inch longer than the 458 SOCOM’s case length of 1.575 inches.

Because of the length restrictions of an AR magazine, the 50 Beowulf is seldom found loaded with bullet weights above 400 grains. With its shorter case design and narrower bullets, the 458 SOCOM can be effectively loaded with nearly any 0.458-inch diameter projectile. This equates to bullet weights all the way up to 600 grains.

As we move towards the base of each case, you will notice a distinct difference in their rim diameters as well. While the 458 SOCOM has the same 0.473-inch rim diameter as the 308, the 50 Beowulf uses a smaller 0.445-inch rim diameter shared with the 6.5 Grendel. This difference means that the cartridges cannot be swapped using the same bolt.

Power

If there is one reason you decided to own a big-bore AR, it’s power. While the 458 SOCOM and the 50 Beowulf are essentially ballistic potatoes regarding range, they are exceptional at maximizing muzzle energy out of the AR-15 platform.

In fact, Underwood’s 350-grain FMJ offering in 458 SOCOM produces 2,116 ft/lbs. of muzzle energy at a velocity of 1,650 feet per second. Considering a standard 5.56/223 produces somewhere between 1,200–1,300 ft/lbs. of muzzle energy, this is a very healthy increase in power.

When we look at Underwood’s 350-grain FMJ offering in 50 Beowulf, we see that it produces a walloping 2,449 ft/lbs. of muzzle energy at a velocity of 1,775 feet per second. This is an increase of nearly 16% more muzzle energy than the 458 SOCOM, which is considerable.

It should be noted, however, that the 458 SOCOM can be loaded to match the muzzle energy figures of the 50 Beowulf, though most factory loadings favor the Beowulf. Regardless, you should not be disappointed with either when it comes to the power department.

One thing you must consider, however, is that the 458 SOCOM is much better suited for subsonic/suppressed fire with its heavier-weight bullet offerings. In fact, several manufacturers produce subsonic load offerings consisting of bullet weights from 450 to 576 grains.

So, although the muzzle energy figures of the factory-loaded 458 SOCOM may leave a little to be desired compared to those of the factory-loaded 50 Beowulf, the latter is far more effective/available at being quiet.

Recoil

Coming from a 5.56 or even a 300 Blackout, the recoil produced by the 458 SOCOM and the 50 Beowulf can be described as nothing short of excessive. In fact, when fired from a 7-pound rifle setup, the 458 SOCOM load referenced above produces approximately 25.7 ft/lbs. of recoil. Fired from the same weight setup, the 50 Beowulf produces approximately 30.5 ft/lbs. of recoil with the load referenced above.

Although these recoil figures are relatively light compared to many cartridges that share the 0.458” and 0.500” bore sizes, both cartridges surpass the recoil of a standard 30-06 (about 25 ft/lbs.). This can take some getting used to, especially for new shooters not accustomed to relatively high recoil levels.

If this recoil worries you, there are several ways to reduce felt recoil to make shooting these cartridges more manageable. Perhaps the most common fix is adding a muzzle device, such as a muzzle brake or a suppressor, which can dramatically reduce recoil. Other options include recoil pads/different stock or simply buying a heavier-weight gun from the start (adjustable gas blocks/heavier buffer weights can reduce recoil as well).

Setups

When choosing a setup chambered in either cartridge, you may notice how limited the number of options is compared to more popular AR-15 chamberings. While this may be the case, the 458 SOCOM is far more popular.

In fact, CMMG, Tromix, Wilson Combat, and several other manufacturers produce high-end setups chambered in the cartridge. If you’re looking for more budget-friendly options, companies such as Bear Creek Arsenal and Radical Firearms produce setups chambered in the 458 SOCOM as well.

If you’re looking for a cost-effective option in 50 Beowulf, however, you will be hard-pressed to find any. That is at least if you want the 50 Beowulf name stamped on it. Due to the licensing and ownership of the Beowulf name, Alexander Arms is virtually the only manufacturer you will find to use the proper 50 Beowulf name on their products.

Although they make the best offerings for this cartridge, they are far from inexpensive for those on a budget. Fear not, however, as more cost-effective options exist with a 12.7x42 stamp instead. Rather than using the 50 Beowulf name, companies such as Bear Creek Arsenal and AR-STONER can chamber uppers in the cartridge with their metric naming.

While these offerings are not at the same quality level as Alexander Arms products, they are a fraction of the cost. Realize, however, that no matter how much or how little you spend on the setup, neither cartridge is considered cost-effective to shoot, regardless of the ammo type you intend to use.

Which One?

While the 458 SOCOM and the 50 Beowulf are both powerful big-bore cartridges primarily chambered in the AR-15 platform, they are very different in many respects. With all these differences, which one should you choose?

Regarding factory-loaded 458 SOCOM offerings, most do not reach the muzzle energy levels of 50 Beowulf offerings. Though this may be the case, it still produces a considerable amount of energy, especially when you consider heavy subsonic offerings. Paired with its higher popularity in both firearm and ammo options, the 458 SOCOM is hard to overlook.  

While the 50 Beowulf is capable of some serious energy figures (at least for the AR-15), that is really the only thing it’s good at. Compared to other big-bore AR cartridges, the 50 Beowulf suffers from more drop and projectiles that are less aerodynamic. However, you can’t say you own a “50 Cal” if you opt for the 458 SOCOM.

Whatever cartridge you decide, get your shoulder ready for some awesome firepower.

--Banana Ballistics