Cartridge Options for Power and Precision in AR Platforms 
                     Cartridge Options for Power and Precision in AR Platforms 
One of the main reasons the AR platform remains so popular is its ability to adapt to different 
calibers. With a simple upper receiver change, shooters can configure their rifles for hunting, 
defense, long-range target shooting, or recreational use. Among the many caliber choices available 
today, two that stand out are the 450 bushmaster upper and the 6.5 grendel complete upper. Each 
offers distinct advantages that appeal to different types of shooters. 
The .450 Bushmaster was developed with hunters in mind, particularly those looking for a 
cartridge capable of handling large game at moderate distances. Known for its impressive stopping 
power, it delivers heavy bullets with enough energy to take down deer, hogs, or even larger animals. 
The straight-wall design also makes it a legal option in certain states where traditional bottleneck 
rifle cartridges are restricted for hunting. For many shooters, a .450 Bushmaster build combines 
the familiar ergonomics of the AR with the performance of a true big-bore hunting rifle. 
The recoil of the .450 Bushmaster is more noticeable compared to standard 5.56 rifles, but many 
users find it manageable, especially with a properly tuned muzzle brake or compensator. Accuracy 
at short to medium ranges is reliable, making it an excellent choice for hunting environments like 
dense woods or brush where long shots are less common. Its effectiveness lies not in distance but 
in the significant energy transfer at closer ranges, ensuring quick and ethical harvests. 
In contrast, the 6.5 grendel complete upper was designed with precision and range in mind. This 
cartridge offers a flatter trajectory and better energy retention compared to standard AR-15 calibers, 
making it highly effective for shooting at extended distances. Whether used for target shooting or 
hunting medium-sized game, the 6.5 Grendel excels where accuracy and consistency are critical. 
One of the key benefits of 6.5 Grendel is its ability to stay supersonic at longer ranges, which 
reduces bullet drop and wind drift. For competitive shooters or enthusiasts who enjoy pushing their 
rifles to longer distances, it provides a reliable and cost-effective way to get more performance out 
of the AR-15 platform. Hunters also appreciate its capability for taking game such as deer and 
antelope at ranges where cartridges like 5.56 NATO begin to lose effectiveness. 
Both the .450 Bushmaster and 6.5 Grendel showcase how versatile the AR platform can be. The 
ability to swap between a hard-hitting big-bore cartridge and a long-range precision round with 
just an upper receiver change highlights the modularity that has made the AR so popular. This 
adaptability allows one lower receiver to serve multiple purposes, saving money while offering 
the freedom to explore different shooting applications. 
Of course, proper maintenance is essential for keeping any build reliable. Big-bore cartridges like 
the .450 Bushmaster generate more recoil and stress on components, so regular inspection of the 
bolt, gas system, and magazines is important. Similarly, rifles chambered in 6.5 Grendel benefit 
from consistent cleaning and attention to optics mounting, since precision shooting often demands 
the highest level of accuracy. 
Ammunition choice also plays a role in performance. Hunters using .450 Bushmaster often select 
soft-point or polymer-tipped rounds for maximum expansion, while 6.5 Grendel shooters may opt 
for match-grade loads to achieve the best accuracy at distance. Testing different loads can help 
each shooter find the balance between accuracy, recoil, and terminal performance that works best 
for their goals. 
Whether the priority is raw power for close-range hunting or precision at extended ranges, both 
cartridges offer compelling reasons to upgrade an AR. The .450 Bushmaster provides the strength 
needed for larger game, while the 6.5 Grendel delivers reach and accuracy that smaller calibers 
struggle to match. Together, they illustrate just how flexible and capable the AR platform can be 
when paired with the right components. 
For those interested in exploring these calibers further, Moriarti Armaments offers a selection of 
uppers and parts designed to help shooters customize their rifles with confidence. Their range of 
options makes it easier to build a reliable firearm suited for hunting, target shooting, or long-range 
practice.