Great Lakes GL-15 RIA .450 Bushmaster 18in 5rd

Description

The Great Lakes GL-15 RIA .450 Bushmaster 18in 5rd is a semi-automatic AR-style rifle built for hunters and shooters who demand reliable stopping power at moderate ranges. Chambered in the hard-hitting .450 Bushmaster, this 18-inch barreled rifle ships with a single 5-round magazine and uses a detachable magazine feed. It features an M-LOK aluminum handguard, a synthetic adjustable stock, and a black Cerakote finish. The GL-15 RIA brings old-school craftsmanship to a modern platform, with a 1:24-inch twist rate that stabilizes heavy projectiles for clean, ethical shots on game.

Manufacturer	Great Lakes Firearms (per manufacturer specs)
Model	GL-15 RIA
Material	7075-T6 aluminum receiver, steel barrel
Compatibility	.450 Bushmaster ammunition, standard AR-15 lower parts (per manufacturer specs)
Finish	Black Cerakote
Weight	Approximately 7.5 lbs (unloaded, per manufacturer specs)
Condition	New

Key Features

• 18-Inch Barrel with 1:24 Twist — Why it matters: The slower twist rate stabilizes heavy .450 Bushmaster bullets (250-300 grains) for consistent accuracy out to 200 yards, ideal for deer and black bear hunting in straight-wall cartridge states.
• M-LOK Aluminum Handguard — Why it matters: The free-float M-LOK design keeps your support hand cool during strings of fire and allows secure mounting of lights, bipods, or slings without adding bulk.
• Black Cerakote Finish — Why it matters: Cerakote provides a durable, corrosion-resistant coating that stands up to wet weather and rough field use, unlike standard parkerization.
• Synthetic Adjustable Stock — Why it matters: The six-position stock lets you adjust length of pull for layered clothing in cold weather or for a compact storage configuration.
• 5-Round Magazine Included — Why it matters: Compliant with many state hunting regulations while still offering quick reloads; the detachable magazine feed is familiar to any AR shooter.

Who It’s For

This rifle is built for the traditional hunter who wants a reliable semi-auto in a straight-wall cartridge. It suits shooters in states like Michigan, Ohio, and Indiana where .450 Bushmaster is legal for deer season. It also appeals to the quality-conscious buyer who appreciates a no-nonsense, field-ready rifle without unnecessary frills.

Pros and Cons

• Pros: Hard-hitting .450 Bushmaster chambering with excellent terminal performance on medium game; durable Cerakote finish resists rust; M-LOK handguard offers modern accessory mounting; adjustable stock fits varied shooters.
• Cons: Magazine capacity limited to 5 rounds out of the box (though higher-capacity mags are available separately); .450 Bushmaster ammo is more expensive and less common than .223 or .308.

Comparison

Feature	Great Lakes GL-15 RIA .450 Bushmaster	Zev Technologies OZ-9C	Geissele Super Duty 11.5
Caliber	.450 Bushmaster	9mm	5.56 NATO
Barrel Length	18 inches	4.5 inches	11.5 inches
Twist Rate	1:24	1:10	1:7
Finish	Black Cerakote	Black Nitride	Black DLC
Magazine Capacity	5 rounds	15 rounds	30 rounds
Weight (unloaded)	~7.5 lbs	~1.8 lbs	~6.4 lbs
Intended Use	Hunting, straight-wall states	Concealed carry, competition	Duty, tactical

FAQ

What is the effective range of the .450 Bushmaster with this 18-inch barrel?

With a 1:24 twist, the GL-15 RIA delivers consistent accuracy on 250-300 grain bullets out to 200 yards. Beyond that, trajectory drops significantly, but it remains effective for hunting at typical woods ranges.

Does this rifle accept standard AR-15 magazines?

No. The GL-15 RIA uses dedicated .450 Bushmaster magazines due to the cartridge’s larger diameter. It ships with one 5-round magazine; aftermarket options in 7- and 10-round capacities are available from brands like Lancer and C Products.

Can I mount a scope on this rifle?

Yes. The upper receiver has a Picatinny rail for mounting optics. The M-LOK handguard allows for a forward-mounted red dot or a scout-style light if desired.

Is this rifle legal for deer hunting in my state?

It depends on your state’s straight-wall cartridge regulations. .450 Bushmaster is legal in Michigan, Ohio, Indiana, Illinois, and several other states. Check your local game laws before purchasing.

What is the twist rate and why does it matter?

The 1:24-inch twist rate is slower than typical .223 barrels (1:7 or 1:9). It stabilizes heavy, slow-moving .450 Bushmaster bullets (250-300 grains) for optimal accuracy and energy transfer on game.

Trust and Service

• ✅ Nationwide delivery (all 50 states)
• ✅ Ships 1-2 business days
• ✅ 30-day returns
• ✅ Secure checkout

Last updated: April 2026

Explore more AR Rifles or check our Hunting Rifles and .450 Bushmaster Ammo.