AR-10 – .300 WSM
$220.00
Estimated production time: 3-8 weeks.
Guaranteed safe checkout
Description
Description
AR-10 .300 WSM Custom Barrel
We make this AR-10 barrel in .300 WSM. Take a look through the available barrel options and the information below before ordering.
Why .300 WSM?
.300 WSM stands for .300 Winchester Short Magnum. It’s a magnum cartridge with a shorter case design than a traditional .300 Winchester Magnum, while remaining a separate chambering.
The WSM name doesn’t mean it fits any AR-10-pattern rifle. Before ordering, confirm the complete rifle and any specialized components needed for this chambering.
Customize Your AR-10 Barrel
- Material and twist: Choose the available barrel steel and rifling twist specifications for this product.
- Length and muzzle: Review the available lengths and muzzle finishes.
- Gas system and barrel profile: Check the gas-system, gas-tube and gas-block size options, including which combinations are offered together.
- Finishing: Fluting, Cerakote and other finishing choices may depend on the barrel configuration.
- Other components: Pay attention to any bolt, bolt-head or customer-supplied component choices.
Before You Order
- Check your platform: AR-10-pattern rifles aren’t all identical. Confirm your receiver, bolt and other relevant components.
- Check your ammunition: Use ammunition specifically appropriate for .300 WSM.
- Confirm your order: This is a custom-made barrel, so review every selected specification and any separately supplied components.
Fitment note: For this magnum chambering, confirm the bolt-carrier group and other related component requirements rather than assuming a universal AR-10 fit.
Barrel Options Explained
Chrome-moly and stainless steel: CM means chrome-moly steel, which needs protection against rust. SS means stainless steel, which resists corrosion better but still needs maintenance.
Twist rate: The listed .300 WSM barrel materials have a 1:10 twist, meaning the rifling makes one full turn every ten inches. That doesn’t describe the barrel’s overall length.
Gas-system length: This product lists rifle-length (about 12 inches) and magnum-length (about 14 inches). These names describe the nominal gas-system layout, not the overall barrel length or the actual measured length of the tube.
What is a gas tube? The tube carries gas from the barrel’s gas block toward the action in a conventional AR system. It’s a separate part from the barrel and block. The Add Gas Tube? choices are for customers who need that component supplied; the tube must correspond to the gas-system layout.
What is the barrel profile? SOCOM and HBAR refer to different outside contours and amounts of barrel material. Lighter profiles generally reduce weight; heavier profiles have more material. Profile choices also determine which gas-block mounting diameter is offered.
Gas-block size and options: The .750 and .875-inch measurements refer to the outside diameter of the barrel where the gas block fits, not its caliber. The listed gas-block add-ons are adjustable styles. Choose None if you already have a compatible gas block. Diameter alone doesn’t guarantee full compatibility with every other part.
Muzzle finishes: Target Crown is an unthreaded muzzle finish. This barrel lists 5/8×24 as its thread choices; thread specifications must match any compatible muzzle device. Magna Port is a porting-style muzzle option with gas-venting cuts intended to help limit muzzle rise, not a separate screw-on device. Gill Cut is a specialty gill-style muzzle cut; contact us about the current pattern and details rather than assuming it functions like porting or threads.
Fluting and muzzle compatibility: Some muzzle treatments aren’t offered with every fluting pattern. The product choices show which combinations are available.
Barrel extension: The steel component at the rear of the barrel has the surfaces the bolt locks against; it isn’t the gas block.
Fluting and coatings: Fluting adds grooves along the barrel’s exterior. Cerakote and other listed finishes affect appearance and surface protection.
What Happens After You Order?
We make the barrel to the specifications on your order. The current estimated production time is 3–8 weeks, not a guaranteed delivery date. Contact us promptly about corrections or updates.
Common Questions About This Barrel
Is .300 WSM the same as .300 Winchester Magnum?
No. Both are .30-caliber magnum cartridges, but they are different chamberings and the ammunition isn’t interchangeable.
Will this fit any AR-10 receiver?
No. Magnum AR configurations can have different requirements. Check your complete platform and components with us before ordering.
What if I need to change my custom order?
Contact us with your order number as soon as possible. Changes may not be possible after work starts, and cancellation terms may apply. See our Refund Policy.
Questions Before You Order?
Questions about .300 WSM or your AR-10 rifle? Email us about this barrel or use our Contact page.
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 issues through an appropriate remedy. Read our Refund Policy and Terms of Service.
Reviews (1)
1 review for AR-10 – .300 WSM
Only logged in customers who have purchased this product may leave a review.












andrew.e.waring (verified owner) –
I would have rather had a barrel in chromoly steel rather then stainless
And also would like to have thinner profile barrels to save on weight overall it shoots straight and I will try to make some more builds