.300 Win Mag

Description

Magnum AR .300 Winchester Magnum Custom Barrel

Deadshot Barrels builds this .300 Win Mag barrel to order for compatible magnum-pattern rifles. Choose from the available material, twist, barrel length, gas-system, profile and finishing options on this page. Some selections affect which additional choices are available, so review the full configuration before ordering.

Why .300 Winchester Magnum?

.300 Winchester Magnum is an established .30-caliber magnum cartridge used for hunting and long-range target shooting. It is a distinct chambering from .300 WSM, .300 RSAUM and .308 Winchester. Those names may look similar, but the ammunition is not interchangeable.

This is a specialized Magnum AR listing, not a standard replacement barrel for every AR-10. The exact rifle and its related components must be confirmed before an order is placed.

Customize Your Magnum AR Barrel

• Material and rifling twist: Choose chrome-moly (CM) or stainless steel (SS), both currently listed with a 1:10 rifling twist.
• Barrel length: The available length selections run from 18 to 26 inches. Some lengths and finishes depend on the other choices in your order.
• Gas system and gas tube: Choose between rifle-length and magnum-length gas-system options. A corresponding gas tube can be selected separately.
• Profile and gas block: The current choices include SOCOM and HBAR contours with .750-inch or .875-inch gas-block mounting diameters, along with compatible adjustable gas-block add-ons.
• Muzzle finish: The menu includes a target crown, Magna Port, 5/8×24 threads and Gill Cut. A thread protector is a separate option.
• Fluting and appearance: Review 6-groove, spiral, diamond and no-fluting choices, plus the available stainless-steel ground finish and Cerakote options. Some combinations are restricted.
• Bolt compatibility: The ordering form includes an acknowledgment about KAK bolt compatibility. The KAK bolt is not included with the barrel and is purchased separately.

Before You Order

• Confirm rifle compatibility: This barrel is intended for a compatible magnum-pattern platform, such as an appropriately configured Noreen BN36. Compatibility with another AR-pattern rifle cannot be assumed from its name alone. Contact Deadshot Barrels to verify your exact rifle and components.
• Confirm the chamber: This product is for .300 Winchester Magnum. Check the rifle and ammunition markings rather than treating other .300 magnum cartridges as substitutes.
• Review the complete configuration: Profile, length, gas-system and muzzle choices can affect the options displayed elsewhere in the order form. Make sure you know which components are included and which are additional selections.
• Ask before placing a custom order: If you’re unsure about fitment or a specialty finish, contact us before checkout.

Barrel Options Explained

Chrome-moly (CM) and stainless steel (SS): These describe the barrel material. Chrome-moly needs protection against corrosion, while stainless steel offers greater corrosion resistance but still needs normal care. Both materials are currently offered with a 1:10 twist in the customer-facing selector.

Twist rate: A 1:10 rifling twist means the rifling makes one complete turn in ten inches. This measurement describes the rifling inside the bore, not the barrel’s overall length.

Barrel length versus gas-system length: Barrel length and gas-system length are separate choices. This page offers barrel lengths from 18 to 26 inches, with rifle-length (nominally about 12 inches) and magnum-length (nominally about 14 inches) gas-system layouts. These labels do not give the barrel’s overall length or an exact gas-tube measurement.

What is a gas tube? On a conventional gas-operated AR-pattern rifle, the gas tube is a component that carries gas from the gas block toward the action. The checkout form offers the applicable gas tube separately, depending on the gas system selected; the gas tube and gas block are not the same part.

Barrel profile: SOCOM and HBAR describe different external barrel contours. The chosen profile affects outside dimensions and which gas-block mounting diameter the order form offers.

Gas block and mounting size: The gas block fits around the barrel at the gas-port area. The .750-inch and .875-inch sizes shown refer to the outside diameter of the barrel at that point, not bullet caliber. This listing has optional adjustable gas blocks or a no-block choice. A matching diameter alone does not confirm full compatibility with a particular rifle.

Muzzle crowns, threads and specialty cuts: A target crown is an unthreaded muzzle finish. The listed threaded choice is 5/8×24, and a thread protector is offered separately. Magna Port describes gas-venting cuts near the muzzle intended to help manage muzzle rise. Gill Cut is a specialty gill-style muzzle treatment. Not every muzzle treatment is offered with every fluting choice; the form specifically excludes Magna Port with spiral and diamond fluting.

Fluting, Cerakote and ground finish: Fluting adds a pattern of grooves along the outside of a barrel; this page lists 6-groove, spiral, diamond and no fluting. Cerakote is an optional protective and cosmetic coating, with its color choices shown after that option is selected. A stainless-steel ground finish is listed separately.

KAK bolt acknowledgment: The product form states that the barrel is headspaced for a KAK bolt and recommends that bolt. It also states that a KAK bolt is not sold with the barrel and must be purchased separately. Review that acknowledgment before ordering and contact Deadshot Barrels with platform or compatibility questions.

What Happens After You Order?

Your barrel is made to the specifications recorded on your order. The current estimated production time is 3–8 weeks; this is an estimate, not a guaranteed delivery date. If you spot a mistake or have a question about your order, contact us as soon as possible with your order number.

Common Questions About This Barrel

Questions Before You Order?

Not sure which options apply to your Magnum AR .300 Win Mag? Email Deadshot Barrels or use our Contact page. We can help clarify the options before your custom order is submitted.

Returns and warranty

Shipped barrels are final sale for discretionary returns. A 15% cancellation fee applies after work has started. We evaluate manufacturing-defect concerns under our warranty and address covered problems through an appropriate remedy. See our Refund Policy and Terms of Service.