OTX 3FO 3-Prong Flash Hider
Compatible with the Castle Blast Shield System
The OTX 3FO 3-Prong Flash Hider by Mid State Firearms is the direct successor to the popular Breek Arms 3FO flash hider. Manufactured to the same proven specifications, it remains fully compatible with both legacy Breek Castle Blast Shields and the new OTX Castle Blast Shield, allowing existing users to expand or replace components without changing their current setup.
Featuring the Castle system’s 13/16×16 outside-threaded interface, the OTX 3FO allows a compatible blast shield to be installed or removed in seconds—giving you the flexibility to run a traditional flash hider or redirect blast forward when conditions call for it.
Superior Flash Suppression
The OTX 3FO is precision machined from heat-treated 4140 steel and finished with a durable black nitride treatment for exceptional corrosion resistance and long service life.
Its three-prong design effectively disperses muzzle gases to minimize visible flash, helping preserve your night vision and reduce your visual signature in low-light environments.
Unlike many conventional flash hiders, the OTX 3FO also incorporates internal gas-disrupting threads that further break up expanding gases before they exit the muzzle, resulting in even greater flash suppression.
Designed for the OTX & Legacy Castle System
The integrated 13/16×16 external threads allow the OTX Castle Blast Shield—or legacy Breek Castle Blast Shield—to thread directly onto the muzzle device.
This modular system lets you quickly switch between:
- Maximum flash suppression
- Forward blast redirection
- Reduced concussion for nearby shooters
- Tool-free installation and removal of the blast shield
The precision cone-style mounting surface promotes excellent concentricity and a secure fit when used with compatible Castle blast shields.
Features
- Direct replacement for the Breek Arms 3FO Flash Hider
- Fully compatible with legacy Breek Castle Blast Shields
- Compatible with the new OTX Castle Blast Shield
- Three-prong flash hider design for outstanding flash suppression
- Internal gas-disrupting threads reduce visible muzzle flash
- 13/16×16 outside threads for Castle blast shield compatibility
- Precision cone interface for secure, concentric lockup
- Heat-treated 4140 steel construction
- Black nitride finish for corrosion and wear resistance
- Made in the USA
Specifications
- Model: OTX 3FO
- Manufacturer: Mid State Firearms
- Caliber: up to 9mm
- Barrel Thread: 1/2×28
- Outside Thread: 13/16×16 TPI
- Material: Heat-Treated 4140 Steel
- Finish: Black Nitride
- Overall Length: 2.12″
- Weight: 2.0 oz
- Includes: Crush Washer
Important Compatibility Information
The OTX 3FO is designed for shooters who want the flexibility of the Castle modular muzzle device system. It is fully compatible with:
- OTX Castle Blast Shield
- Legacy Breek Arms Castle Blast Shield
- Any Castle-compatible accessory utilizing the 13/16×16 mounting interface
Whether you’re replacing an original Breek Arms muzzle device or building a new rifle around the OTX system, you’ll get the same proven performance with continued support from Mid State Firearms.gher muzzle pressures. Installation of all Breek Arms muzzle devices are very straightforward and require basic hand tools.
sound of freedom – This was a great set up. I loved being able to customize the set up. Only issue I had was my own fault as a newb to building these. I used a heavy barrel in a slim hand guard. It makes adding attachments tough with clearances. Hoping someday to also get an AR10 from here.