.450 Bushmaster Complete Upper Receivers
AR15Parts.com builds .450 Bushmaster complete upper receivers to order for shooters who want thumper-class big-bore power on the AR-15 platform. Every upper is assembled, headspaced, and function-checked in our shop. The .450 Bushmaster delivers devastating energy on target with 250-grain bullets at 2,200+ fps. It is one of the most popular big-bore hunting cartridges for the AR-15, delivering enough energy to cleanly take deer, bear, and hog at close to medium range. As a straight-wall cartridge, it is also legal for deer hunting in restricted states. Configure your .450 Bushmaster upper with your choice of barrel length, handguard, muzzle device, and optional BCG and charging handle.
Why Shooters Choose AR15Parts.com for .450 Bushmaster Uppers
Every .450 Bushmaster upper is assembled in-house, headspaced, and inspected before shipping. Built to your specifications with quality components designed for big-bore operating pressures. No FFL required.
How to Choose the Right .450 Bushmaster Upper
Barrel Length & Gas System
.450 Bushmaster uppers are available in 16", 18", and 20" barrel lengths with carbine-length or mid-length gas systems. A 16" barrel creates a compact, hard-hitting hunting rifle. The 1:24 twist rate is standard for the cartridge's heavy, large-diameter projectiles.
Complete Upper vs. Barreled Upper
Complete uppers include BCG and charging handle. The .450 Bushmaster requires a dedicated bolt in a standard AR-15 carrier, so we recommend a complete upper if you don't already own a .450 Bushmaster BCG.
Key Specifications
Muzzle Velocity: \~2,200 fps with 250gr Effective Range: 250 yards Barrel Twist: 1:24 Recoil: Moderate to heavy (\~22 ft-lbs) Platform: Standard AR-15 lower receiver Cartridge Type: Straight-wall
.450 Bushmaster Upper Compatibility
The .450 Bushmaster uses a dedicated .450 Bushmaster bolt in a standard AR-15 carrier. It feeds from modified single-stack AR-15 magazines. The upper drops onto any mil-spec AR-15 lower with no modification. Suppressor compatibility is available with .45-caliber suppressors rated for rifle pressures.
Best Uses for .450 Bushmaster Uppers
The .450 Bushmaster is a big-game hunting cartridge built for close to medium range. Deer, bear, and hog hunters choose it for its massive energy transfer and large wound channels. The cartridge's straight-wall design makes it legal in states that restrict bottleneck cartridges for hunting. At the range, .450 Bushmaster delivers the kind of authority you can feel with every trigger pull. It is not a high-volume plinking cartridge — it is a purpose-built hunting tool that also happens to be a blast at the range.
Frequently Asked Questions
What is included in a complete .450 Bushmaster upper?
Complete uppers include the upper receiver, barrel, gas system, handguard, and muzzle device — assembled and headspaced. BCG and charging handle available as add-ons.
Will a .450 Bushmaster upper fit my AR-15 lower?
Yes. Our .450 Bushmaster uppers fit any standard mil-spec AR-15 lower receiver.
Can I use my 5.56 BCG?
No. The .450 Bushmaster requires a dedicated bolt. The carrier is standard AR-15, but the bolt itself is specific to .450 Bushmaster.
Is .450 Bushmaster legal in straight-wall states?
Yes. The .450 Bushmaster is a straight-wall cartridge, legal for deer hunting in Ohio, Iowa, Indiana, Michigan, and other straight-wall restricted states.
What is the effective range?
The .450 Bushmaster is effective for hunting to approximately 250 yards. It excels at close to medium range.
What magazines does .450 Bushmaster use?
.450 Bushmaster feeds from modified single-stack AR-15 magazines.
How long does shipping take?
Most in-stock configurations ship within 3-5 business days. Custom builds may take 2-3 weeks. Orders over $99 ship free.
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