Rearden Manufacturing Group Llc Fhd Flash Hider .578X28 Square Shoulder Black Nitride

The Rearden FHD flash hider in .578×28 with square shoulder is a precision muzzle device engineered for shooters running Plan B-type suppressor mounts or Rearden Atlas and Atlas XL systems. This is the updated version with enlarged wrench flats for easier installation and adjustment. The black nitride finish delivers both durability and a tighter seal when properly installed—critical for suppressor performance and consistency shot to shot.

Flash hiders serve a dual purpose: they reduce visible muzzle flash and they provide a mechanical interface for suppressor mounting. The FHD's square-shoulder design ensures repeatable alignment with your suppressor, and the .578×28 thread pattern is the standard host for modern Rearden cans and compatible third-party suppressors. Installation requires attention to detail—the muzzle device must be torqued to spec and properly rockset to your barrel for the nitride finish to work as intended and for the seal to remain consistent over time.

The 17-4 PH H900 stainless steel construction with nitride hardening (67 HRC surface) resists wear and corrosion. This is a no-overrun design, meaning it won't creep forward under recoil impulse when properly secured. Keep in mind that shims are not included; depending on your barrel's thread relief, you may need them to time the device perfectly straight. As always, use an alignment rod during setup and clean all threads and tapers before mounting your suppressor.

Key Features

• Plan B-type suppressor mount compatible
• Atlas and Atlas XL Adapter compatible
• Enlarged wrench flats for easier installation and removal
• Square-shoulder design for repeatable suppressor alignment
• Black nitride finish (67 HRC) for seal integrity and durability
• 17-4 PH H900 stainless steel construction
• No-overrun design prevents forward creep under recoil
• .578×28 thread pattern

Specifications

Frequently Asked Questions

What suppressors and mounting systems does the Rearden FHD work with?

The FHD is compatible with Plan B-type mounts and Rearden Atlas and Atlas XL suppressor systems. Always verify that your specific suppressor or adapter is rated for .578×28 Plan B compatibility before purchase.

Do I need shims for this flash hider?

Shims are not included. Depending on your barrel's thread relief, you may need shims to time the device perfectly straight. Many barrel manufacturers mill a thread relief; if yours doesn't, shims will likely be necessary.

How do I install and torque the Rearden FHD flash hider?

Torque the muzzle device to approximately 30 ft-lbs and rockset it to your barrel once installed. Use an alignment rod during setup to ensure the entire system is square. All threads and surfaces should be clean before installation. When mounting your suppressor, torque it to 10 ft-lbs and verify alignment. Do not install on Q suppressors, as that voids compatibility.

What makes the black nitride finish important on a muzzle device?

The black nitride finish (67 HRC surface hardness) provides a tighter seal when the flash hider is mated to your suppressor. However, this benefit depends on proper installation: the device must be torqued and rockset to your barrel correctly, and all threads must be clean before mounting the can.