Rearden Manufacturing Group Llc Spb Muzzle Brake 0.375 9/16-24 Threads Square Shoulder Black

The Rearden SPB muzzle brake in .375 with 9/16-24 threads is a precision-engineered muzzle device built for shooters running suppressor-ready setups. Built from 17-4 PH H900 stainless steel and finished in black nitride, this brake is engineered to pair with Plan B-compatible suppressor mounts and integrates seamlessly with both Atlas and Atlas XL adapters. The square shoulder design ensures proper indexing against your barrel for a consistent, repeatable platform—critical when you're stacking tolerances in a suppressed rifle system.

The nitride finish delivers a hardness of 67 HRC and contributes to a tighter seal when your suppressor is mounted, but that performance depends on correct installation. The brake should be torqued to 15–25 ft-lbs and secured with Rockset to prevent loosening under recoil. Alignment is everything in a suppressed setup, so use an alignment rod during installation to confirm the entire system tracks true. Shims are included to help dial in fit (except on SR25/M110 and 11/16×24 variants).

This is a muzzle device, not a suppressor, and is designed to accept a suppressor on its threaded interface. When mounting your can, ensure threads and tapers are clean, then torque the suppressor to 10 ft-lbs. If you're planning to run a Q suppressor, be aware that Rearden voids warranty in that configuration—so confirm compatibility with your chosen silencer before you commit.

Key Features

• 17-4 PH H900 stainless steel construction
• Black nitride finish (67 HRC surface hardness) for durability and corrosion resistance
• Compatible with Plan B suppressor mounts
• Works with Atlas and Atlas XL adapters
• Square shoulder design for consistent barrel indexing
• Shims included for fit optimization
• Threadless overrun on standard Atlas adapter (~1.050" of material ahead of threads)

Specifications

Frequently Asked Questions

What suppressor mounts does this brake work with?

The SPB is engineered for Plan B-compatible suppressor mounts. It integrates with both Atlas and Atlas XL adapters. Be aware that Rearden voids the warranty if you run a Q suppressor on this brake, so confirm your can and mount combination before purchase.

Do I need to use an alignment rod during installation?

Yes. Always use an alignment rod when installing the SPB to ensure your entire suppressed system is properly aligned. This is critical for consistent performance and suppressor stability.

What torque specs should I follow?

Torque the muzzle brake to your barrel at 15–25 ft-lbs, then Rockset it to prevent loosening. When mounting your suppressor, torque it to the brake at 10 ft-lbs. Ensure all threads and tapers are clean before assembly.

Are shims included?

Shims are included with the standard SPB to help optimize fit, except on SR25/M110 and 11/16×24 thread versions.