Great Lakes Firearms AR-15 .450 Bushmaster 18" ODG/SS 5-Round Rifle

The Great Lakes Firearms AR-15 .450 Bushmaster is a purpose-built rifle for hunters and shooters who want serious stopping power in a compact, tactical platform. Chambered in .450 Bushmaster—a cartridge that punches well above its weight for big-game hunting—this 18-inch semi-automatic rifle combines the ergonomics and modularity of the AR platform with ballistics designed for medium-to-long-range hunting. It's an excellent choice for hunters working thick cover or wanting a rifle that bridges the gap between traditional centerfire hunting rifles and specialized tactical builds.

The rifle comes equipped with a mid-length gas system and 0.750 gas block tuned for the heavier recoil impulse of the .450 Bushmaster, delivering reliable cycling while keeping overall length and weight manageable. The 18-inch barrel is available in 416R stainless steel or 4150 CRMOV nitride, both with a 1:24 twist rate and 11/16 x 24 threaded muzzle. The barrel arrives with a muzzle brake already fitted—designed to be wrench-tightened without thread locker. A full-length Picatinny rail foregrip (15.25 inches of 6061 aluminum) and oversized 7075 aluminum upper receiver provide rock-solid mounting for optics, lights, and other accessories.

Built on a 7075 aluminum lower receiver with mil-spec controls, the rifle features a standard polymer grip and a milspec trigger breaking at 5.5–6 pounds. It ships with one 5-round magazine and uses modified M4 feed ramps. Finished in Cerakote, the rifle balances durability with a professional appearance. At 6.4 pounds, it's light enough for serious field work without sacrificing barrel rigidity or accuracy potential. No sights are included, leaving the rail clear for your optic setup.

If you're looking for a .450 Bushmaster AR-15 built on quality American components with the ergonomics you know and the ballistics for serious hunting, Great Lakes Firearms delivers a rifle that works as hard as you do in the field.

Key Features

• Semi-automatic .450 Bushmaster caliber with proven hunting performance
• 18-inch barrel with 1:24 twist rate, available in stainless or nitride finish
• Mid-length gas system with 0.750 gas block optimized for .450 recoil
• Threaded muzzle (11/16 x 24) with muzzle brake included
• Full-length Picatinny rail handguard for optics and accessory mounting
• Oversized 7075 aluminum upper receiver for strength and accuracy
• 7075 aluminum lower receiver with mil-spec controls
• Includes one 5-round magazine and muzzle brake
• Cerakote finish for durable, professional appearance
• Lightweight at 6.4 pounds for field versatility

Specifications

Frequently Asked Questions

What barrel material does the Great Lakes Firearms .450 Bushmaster come with?

The barrel is available in either 416R stainless steel or 4150 CRMOV nitride. Both are 18 inches long with a 1:24 twist rate and 11/16 x 24 threads. Choose stainless for maximum corrosion resistance or nitride for a durable, hard-wearing finish.

Does it come with optics and sights?

No, the rifle ships with no sights. However, the full-length Picatinny rail handguard and oversized upper receiver provide ample mounting surface for your choice of optic, red dot, or magnified scope.

What's included in the box?

The rifle comes with one 5-round magazine and a muzzle brake (already installed). The muzzle brake is designed to be wrench-tightened without thread locker.

Is this rifle suitable for hunting?

Yes. The .450 Bushmaster cartridge is purpose-built for hunting medium-to-large game, and the 18-inch barrel with mid-length gas system is optimized for reliable performance with this round. The Picatinny rail system makes it easy to mount hunting optics.

Does the safety lever work for left-handed shooters?

The rifle features a standard (right-handed) safety lever, not an ambidextrous control. Left-handed shooters may want to consider aftermarket ambi safety options if desired.