Otter Creek Arms Ocl-843 Otb Muzzle Brake Black Nitride 5/8X24

The Otter Creek Arms OCL-843 OTB Muzzle Brake is a 5/8x24 threaded adapter built for shooters running OPS 12th model suppressors—the OCM5 or AEM5—on barrels that would otherwise need custom work or proprietary collars. Machined from H900 heat-treated 17-4 stainless steel and finished in black nitride, this one-piece muzzle brake combines the function of a timing adapter with a muzzle device, letting you mount your suppressor to any 5/8x24 barrel with 0.75" or less outside diameter and a minimum of 2.05" of exposed barrel measured from the shoulder. If you've been holding off a build because your barrel didn't fit the standard OTB mount, this solves that problem without a trip to a gunsmith.

The real value here is in the included shim kit. Unlike the standard OTB flash hider, the OTB Muzzle Brake ships with a full set of shims for proper timing—and using shims is the only approved method for timing this device. That built-in hardware saves you a separate purchase and keeps everything in one box. The black nitride coating delivers durability and a clean look, though Otter Creek also offers a raw heat-treat finish if that's your preference.

Installation is straightforward on any 5/8x24 threaded barrel. One critical detail: do not use a crush washer with this muzzle device—doing so voids the warranty. Hand-time the brake with your shims until the suppressor sits perfectly, and you're ready to run. Built tough for long-range rifles, precision ARs, and any setup where suppressor alignment matters.

Key Features

• 5/8x24 threaded muzzle brake and OPS 12th model suppressor adapter in one piece
• H900 heat-treated 17-4 stainless steel construction for durability and corrosion resistance
• Black nitride finish (raw heat-treat option also available)
• Works with barrels up to 0.75" OD with 2.05" minimum exposed barrel length
• Includes shim kit for proper suppressor timing
• No custom barrel work or proprietary collars required
• Compatible with OCM5 and AEM5 suppressors

Specifications

Frequently Asked Questions

Will this work with my suppressor?

The OTB Muzzle Brake is designed for OPS 12th model suppressors, specifically the OCM5 and AEM5. If you're running a different suppressor pattern, this adapter won't be compatible.

Can I use a crush washer to time this muzzle brake?

No. Do not use a crush washer with the OTB Muzzle Brake—it voids the warranty. The included shim kit is the only approved method for timing. Hand-tighten the brake and use shims to achieve perfect alignment with your suppressor.

What barrels will this fit?

The OCL-843 fits any barrel with 5/8x24 threads, an outside diameter of 0.75" or less, and a minimum of 2.05" of exposed barrel measured from the shoulder. No custom barrel work is needed.

What's included in the box?

The muzzle brake comes with a shim kit for timing your suppressor. Unlike some other OTB adapters, the shim set is included, so you won't need to purchase it separately.