AR-10 – .338 RCM

Description

AR-10 .338 RCM Custom Barrel

We make this AR-10 barrel in .338 RCM. Take a look through the available barrel options and the information below before ordering.

Why .338 RCM?

.338 RCM stands for .338 Ruger Compact Magnum. It uses a compact magnum cartridge design and a .338-caliber bullet, giving it a different character from the more familiar .308 Winchester.

This is a specialized chambering, not another name for .338 Federal. It deserves an extra check of ammunition and complete rifle compatibility before an order is placed.

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 .338 RCM.
• Confirm your order: This is a custom-made barrel, so review every selected specification and any separately supplied components.

Fitment note: The existing product guidance calls for verifying applicable DPMS-style bolt-carrier group fitment.

Barrel Options Explained

CM and SS: CM is chrome-moly steel, which needs protection against rust. SS is stainless steel, which resists corrosion better but still needs regular care. Check the listed material/twist choices for this chambering.

Twist rate: A marking such as 1:10 means the rifling makes one complete turn over ten inches. It isn’t a barrel-length measurement.

Gas-system length: Pistol, carbine, mid-length, rifle and magnum are different nominal gas-system layouts. The configuration for an individual chambering determines which are appropriate.

What is a gas tube? In a conventional AR system, the gas block directs some gas through a small tube toward the action. The tube is a separate component from the barrel and gas block. If you need one supplied, review the Add Gas Tube? option where offered. Gas-tube selection corresponds to the applicable gas-system layout.

Barrel profile: Labels such as Light, SOCOM, HBAR and Bull describe different exterior barrel contours and amounts of material. Lighter contours generally weigh less than heavier ones.

Gas-block size and selection: Gas-block sizes such as .750 and .875 identify the barrel’s outside diameter where the block fits. The block can be selected as an add-on where offered. Fixed and adjustable designs are different options. Customers with their own compatible block can choose a no-block option where available; matching diameter alone doesn’t establish full compatibility.

Muzzle finishes: A target crown is an unthreaded muzzle finish. Muzzle threads are specified by their diameter and pitch. Porting-style finishes such as Magna Port vent gas through cuts near the muzzle. Gill Cut is a specialty cut pattern; contact us to confirm the specific finish offered on a particular order.

Barrel extension: This steel component at the rear of the barrel provides the locking surfaces for the bolt. It isn’t the gas block.

Fluting and finishes: Fluting cuts grooves along the outside of the barrel. 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

Questions Before You Order?

Questions about .338 RCM 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. See our Refund Policy and Terms of Service.