The 458 SOCOM and Its Alternatives in AR-15 Big-Bore Builds

Introduction

When discussing big-bore cartridges for the AR-15 platform, the 458 SOCOM comes up frequently due to its respected performance. However, it's not the only option, and other rounds like the 450 BushMaster BM offer unique advantages. This article explores the pros and cons of each, helping shooters make informed decisions for their builds.

458 SOCOM: A Specialized Round

The 458 SOCOM is a specialized cartridge designed for very specific purposes. It uses 0.458-inch bullets, making it significantly different from the more common 0.452-inch bullets used in the 450 BM. This rounds popularity is largely due to its niche applications and the ability to use shorter barrels, which is beneficial for suppressed rifles.

One of the key points in favor of the 458 SOCOM is its suitability for hunting. In some states, it is legally permitted where the 450 BM may not be. Additionally, the change from standard rifle calibers like 223/5.56 to 458 SOCOM is relatively straightforward, whether for AR platforms or bolt-action rifles like the Savage Scout or Ruger. Moreover, SOCOM-chambered magazines are more problematic, adding another layer of complexity for those looking for simplicity and standardization.

450 BushMaster BM: A Good Design with Room for Improvement

The 450 BushMaster BM is described as a good design, though not without its flaws. It employs 0.452-inch bullets, which are headed by “pistol” bullets instead of the “rifle” bullets seen in the 458 SOCOM. For civil applications, the 450 BM often seems to be a better choice due to its versatility and ease of use.

More importantly, the 450 BushMaster has the rifle-like performance of a 0.45–70 loading, packaged in an AR-15 platform. This makes it an excellent choice for big-game hunting. The 450 BM also offers the versatility to run as one of several uppers on a common lower, making it more convenient for those who want to switch between different calibers without changing their entire rifle. A registered SBR, for example, can run both the 458 SOCOM and the 450 BM, offering a versatile hunting and defensive platform.

Real-World Applications

Both the 458 SOCOM and the 450 BushMaster BM are modern renditions of the classic 0.45-70 cartridge, which has seen use in various forms for over 150 years. The 458 SOCOM is a specialized round that excels in specific applications, while the 450 BushMaster BM offers a more general and versatile option.

Users of the 458 SOCOM often swear by it, finding it effective for their purposes. However, for a more general-purpose big-bore AR-15 build, the 450 BushMaster BM might offer an edge, especially in terms of legal hunting versatility and the ease of use in a wide range of applications.

Regardless of the specific cartridge chosen, the key is to understand the limitations and potential of each. Neophytes and seasoned shooters alike can benefit from carefully considering their needs and the features of each cartridge before making a selection.

In the end, whether you opt for the 458 SOCOM or the 450 BushMaster BM, it's important to remember that understanding the reality of your needs and the capabilities of each cartridge will ensure a successful and enjoyable shooting experience. So, keep well and shoot straight!