Kak Retro Ar Ext Flsh Hdr 4" 1/2X28

The Kak Industry Retro AR Extended Flash Hider is a 4-inch muzzle device built to extend a 12.5-inch barrel to legal non-NFA length when pin and welded. Drawing inspiration from the classic XM-177 Moderator, this flash hider combines period-correct styling with practical function—ideal if you're building a compact AR with a mid-length or rifle-length handguard and need to thread the legal barrel-length gap. With a 1/2x28 thread pitch, it threads onto most standard .223/5.56 uppers and ships ready for a competent gunsmith to pin and weld in place.

The five flash-hiding ports help break up muzzle flash, giving you better sight picture control in low light and reducing signature downrange. The body is heat-treated and phosphate-coated for durability, with milled flats to simplify installation wrench work. A .125-inch pre-drilled hole makes pin-and-weld setup straightforward for a smith who knows the job. Note that a crush washer is not included, so source one if your setup calls for it.

This is a no-frills, honest muzzle device for shooters who want practical XM-177 aesthetics without the NFA paperwork—just the geometry and performance of a bygone military platform adapted to modern civilian barrel rules.

Key Features

• Extends 12.5" barrel to legal non-NFA length when pin and welded
• Five flash-hiding ports for reduced muzzle signature
• Heat-treated and phosphate-coated steel construction
• Milled flats for installation tool access
• Pre-drilled .125" hole ready for pin-and-weld attachment
• 1/2x28 thread pitch for standard .223/5.56 uppers
• XM-177 Moderator-inspired design

Specifications

Frequently Asked Questions

Will this flash hider work with my 12.5-inch barrel?

Yes—that's the core use case. This extended flash hider is designed to extend a 12.5-inch barrel to legal non-NFA length when pin and welded, making it a practical way to hit the 16-inch overall minimum without registering as an SBR or Short-Barreled Rifle.

What thread pitch does this fit?

The Kak Retro AR Extended Flash Hider has a 1/2x28 thread pitch, which is the standard for most .223/5.56 uppers. Verify your barrel's thread pitch before ordering.

Can I attach this without pin and welding?

This device is designed for permanent pin-and-weld installation. It comes pre-drilled at .125 inches to accept a pin, and should be welded by a qualified gunsmith to stay in compliance with NFA requirements for barrel length.

Does this come with a crush washer?

No. A crush washer is not included, so you'll need to source one separately if your setup requires it. Your gunsmith can advise on fitment for your specific application.