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***TUTORIAL*** Pinning Muzzle Brakes to FSB

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About a month ago I permanently pinned a muzzle brake to a front sight block for legal reasons and figured I would take some pictures and draw some diagrams to share with you guy. I finally got around to doing this and here is my tutorial. Below are diagrams, followed by pictures, at the bottom are some FAQs of stuff people have asked me about this.


As with my other FSB swap tutorial, this method requires only the most basic of tools and can be done at home. The prodcedure is done with the Front Sight Block and Muzzle Brake unit themselves, prior to installing the front sight block on the gun. Tools required: Drill, 8-32 tap, 8-32 screws, small file, thread locker, dremel. This can also be done simply with a drill, pins of some sort, and a small file.


Please keep in mind this is for informational purposes only. I don't know your state's laws, and would strongly suggest you check with your state's laws to ensure this is OK where you live.


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Q: Why Screws? Why not pins?

A: This can be done just as well substituting 8-32 screws with pins, drill rod, even peened nails, will all work perfectly for this. I used the screws and tap simply because that is what I had on hand.


Q: Why three of them? Wouldn't just one pin work?

A: One pin would work just fine. That alone would be more than enough to keep it from coming off. I went with three because, since I was doing this for legal reasons, I figured I may as well make it so that there isn't even a shred of doubt that this is permanent.


Q: JB Weld? On a gun?

A: Yes, I used JB weld instead of red loc-tite. The reason being is, this part is not bearing any load. The only reason for thread locker in this application is simply to keep the screw from backing out. The muzzle gets very hot during firing, red loc-tite melts at 270 F, JB weld does not melt until 600 F. I went with JB weld as a thread locker as it will better withstand the temperatures the muzzle reaches.


Q: Why not weld it?

A: Yes, you could weld it, however I do not have any welding equipment, and this is a tutorial for permanently attaching without welding equipment. I also like that the pinned brake does not even look modified except upon very close inspection.


Any other questions please feel free to ask!

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  • 4 weeks later...

Curious, what legal reasons require permenent attachment of a muzzle device to a FSB?


If you're talking about shortening the barrel to <18" and getting it back over with the muzzle brake, then I don't think that meets the requirement in a couple of ways. It's not permanently attached "to the barrel", unless you're also permenently attaching the FSB by one of these methods, and it doesn't meet the description of what is accepted as "pemanently attached".


"Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over."


This is not a short barreled rifle, the firearm's barrel is over 16" without the muzzle brake, the addition of the brake brings the rifle to ~18-19" inches. No modifications have ever been made to shorten the barrel length of this firearm in any way. I think you are confusing the lengths for rifles/shotguns, rifles must be over 16" and shotguns must be over 18" according to Federal Law as well as the laws of my state.


Nothing here is intended as legal advice, or information on laws. If you're doing barrel modifications this isn't the thread for that. This specific application was done to comply with a state level "assault weapons" ban on flash suppressors/threaded barrels, many of which states have a different definition, or no definition at all, of what constitutes permanent attachment of a muzzle device for AWB purposes. This particular modification was done to display that there is no way a flash suppressor could be readily attached to the rifle. The law requires that the rifle not have a "flash suppressor or threaded barrel capable of accommodating a flash suppressor" and in its configuration has neither of those things.

Edited by Classy Kalashnikov
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  • 1 year later...

got any good links for shearing the sleve off? i already cut it down the length and around and tried hammering it off but i was wondering if u had any better ideas

Ok, I got you. I didn't pay close enough attention to the pic to realize that was a rifle.


You just mentioned that it was for legal reasons, but didn't say exactly which ones. I just wanted to make sure someone didn't think it was to extend the barrel length. :rolleyes:


Good call, thanks a lot.

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