Breek Arms Castle Blast Shield for Outside Threaded Muzzle Devices

SKU: BRK4038

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Thread-On Blast Shield for Breek Arms Muzzle Devices

This is the perfect add-on for any of Breek Arms’ Outside Threaded Muzzle Devices.  While this device doesn’t thread directly onto the barrel of any AR-15, the Castle Blast Shield does slip onto the coarse outside threads of the muzzle device itself.  For flash hiders, this has the effect of reducing effectiveness overall.  However, it also reduces concussion and noise for the shooter by throwing blast downrange.  Effectively, this blast shield turns your muzzle device into a linear compensator, at a price that’s lower than most high end single-purpose muzzle devices.  Since this muzzle device does a very simple job, it’s also a very lightweight design.  Durable 6061 T-6 aluminum keeps the weight under 2 ounces in total, the overall length makes it fit flush with Breek’s full-length flash hiders and brakes.

This blast shield is a great product that offers value few other manufacturers can, especially if you plan on pinning and welding.  One of Breek Arms’ full-length muzzle devices will bring a 14.5 inch barrel up to 16 inches.  Add in the castle, and you can choose between reducing flash or concussion whenever you’d like.


  • Threading: 13/16 x 16 TPI
  • Compatibility: All Breek Arms Outside Thread Muzzle Devices
  • Outside Diameter: 1.26″, fits inside most slimline handguards
  • Length: 2.15″, fits flush with 3FO Flash Hiders
  • Weight: 1.6 oz
  • Material: 6061 T6 Aluminum
  • Finish: Hardcoat Anodized Black

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Customer Reviews

Based on 5 reviews
Tristen Mortel

I couldn’t recommend this product more to anyone! I put this on my dream AR-Pistol build and I love it. It’s absolutely phenomenal on sound and utility to redirect the sound down range focused

Thank you for your fantastic review! We are thrilled to hear that the Breek Arms Castle Blast Shield has exceeded your expectations and is working well on your AR-Pistol build. We appreciate your recommendation and are happy to know that it has enhanced the sound and functionality of your firearm. Thank you for choosing Breek Arms and happy shooting!

Vance Nethery
Worth it

For cqb this is a perfect addition to the tri-cut break. At night I literally notice the flash from my ejection port more than my muzzle.

If you don't want to worry about flash, or gases getting in your way with a pistol build I'd suggest this highly.

Thanks for sharing your opinion! We're glad to hear that the shield is worth the money and helps with flash and gases.

Shukuri - GZ265825 Tavkelishvili
Breek Arms Castle, Super.

AT 3 is super, an excellent thing, the visual quality is super, my AR 15 has become even more beautiful, and most importantly, the sound has moved forward and is less disturbing. Super, I would like to wish for even more choice, more brands, thanks AT 3!!!

Thank you for your feedback on the Breek Arms Castle Blast Shield! We are thrilled to hear that you are satisfied with the quality and aesthetics of our product. We will definitely consider expanding our selection to include more brands in the future. Thank you for choosing AT 3 and happy shooting!

Donavan Hinson
Excellent Muzzle Device

It works really well for forward gas dispersal, which helps keep the recoil linear and against the shoulder. It's a fantastic muzzle device, and I plan to buy more in the future.

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.

Awesome product

Great value! Works well, looks amazing!

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.