.450 Bushmaster Uppers

450 Bushmaster Complete Upper Options

MSF 16″ .450 Bushmaster Upper Receiver Assembly

MSF 18″ .450 Bushmaster Upper Receiver Assembly

Hunting With The Legendary 450 Bushmaster Upper

As the AR-15 has gained more and more popularity as a hunting rifle, the 450 Bushmaster has also become a sought-after “big bore” cartridge. For those looking for the best 450 Bushmaster complete upper, Mid State Firearms has all the components and options you can dream of–so you can make your weapon a truly custom work of art. 

A Little Historical Context

The .450 Bushmaster Upper Receiver has a storied origin, pioneered by Colonel Jeff Cooper, a seasoned US Marine with combat experience in WWII and the Korean War. Frustrated by the limitations of .223 Remington/5.56x45mm NATO cartridges. Inspired by the concept of utilizing an AR-15 platform, Cooper envisioned a cartridge similar to the .45 ACP pistol cartridge but with increased size, accuracy, and armor-piercing capabilities.

LeMag Firearms explored Cooper’s idea, but it was Bushmaster who secured the license.

Hornady, commissioned by Bushmaster, developed the .45 Professional for this concept. However, Hornady’s innovation led to further improvements, such as shortening the length to accommodate flex-tip bullets, resulting in the birth of the .450 Bushmaster.

Building a Rifle With a 450 Bushmaster Upper

Building your own .450 Bushmaster rifle is pretty straightforward. If you already own an AR-15 rifle, you’re halfway there.

All you need to do now is remove the existing upper, install your .450 Bushmaster upper assembly, and switch out the magazines.

Customization Options for Your 450 Bushmaster AR-15 Upper

Mid State Firearms offers rifle builds that include endless customization. We carry high-quality .450 Bushmaster uppers with various barrel lengths, such as 18-inch or 16-inch, allowing you to choose the one that suits your preferences. Our 450 Bushmaster Upper Receiver Assemblies include:

• Receiver
• Bolt
• 18-inch barrel
• Handguard
• Muzzle device

Enhance your upper with additional components:

• Advanced bolt carrier groups
• Specialized charging handles
• Tactical foregrips
• Precision optics and lighting systems

Key Advantages of the 450 Bushmaster Upper Receiver

Compatibility

• Direct fit for existing AR-15 5.56 NATO lower receivers
• Minimal modification required
• Some 5.56 NATO magazines remain compatible

Durability

Choose from a range of upper receiver materials:

• Lightweight aluminum
• Rugged chrome-moly
• High-strength steel

Optimal Performance 

• 18-inch barrel provides ideal balance
• Designed for medium-range big game hunting
• Seamless mil-spec installation

Frequently Asked Questions

Can I Convert My Existing AR-15 to .450 Bushmaster?

Yes! Our 450 Bushmaster Upper Receivers are designed for easy conversion. Simply remove your current upper and install our complete upper assembly.

What Game is the .450 Bushmaster Best Suited For?

The .450 Bushmaster excels in taking down large game at close to medium ranges, including elk, deer, and bear. It’s particularly effective in dense brush-hunting environments.

Are These Uppers Difficult to Install?

Not at all. Our 450 Bushmaster AR Uppers are mil-spec and designed for straightforward, gunsmith-free installation.

Shop for Your 450 Busmaster Upper Assembly Here

Transform your AR-15 into a dedicated hunting rifle with our precision-crafted 450 Bushmaster Upper Receivers. Whether you choose the 16″ or 18″ configuration, you’re investing in a game-changing hunting solution that can be completely customized. Get your 450 Bushmaster AR Upper and feel the difference!