NY state (possibly NJ also) does not allow threaded barrels on AR15's, so screw on muzzle brakes are a non-no. Does anyone know if there's some material/process I can use to permanently attach a screw-on brake? I was surprised to find that Alexander Arms uses Loctite 620 to permanently attach their brakes, but there's are a sleeve fit (no threads). I do not want to get involved in silver soldering if I can avoid it. Thanks!

I use Loctite 680. It is removable with heat so may not work on an AR-15. I simply machine the break or suppressor to neatly fit the barrel. When the overhang is substantial, I use an alignment device. Epoxy works too but can be a bitch to get off (takes too much heat).


There are two joints on this muzzle break, the smaller being the one on the barrel. (This muzzle break has no side ports - it acts like a 'medium' suppressor).

I wouldn't recommend doing a thread on muzzle brake unless it's exactly the same diameter as your barrel, because at some point you may want to take something off the barrel and if the item won't clear the brake, then you are done. To avoid this scenario, I machine my brake directly into the barrel.

That said, if NY is as anal as BATF, then you will probably need to have the thread on brake pinned and welded.

The ATF considers a brake "permenant" if it is either pinned or silver soldered (actually "brazed," or "hard soldered") after it was threaded to the muzzle. THis is why you can own an M4orgery with an actual 14.5" barrel without having to buy a stamp for an SBR.

Again, that is the federal law and not your state law. If the NY law says it follows the ATF guidelines, then you can pin the brake after threading it onto the end of your barrel.

just send your barrel to westpac, I have seen one of his integral brakes, they are fun to look at just to see the machining if for nothing else. he claims they even increase the speed of the bullet slightly.

Hey this works to. machine the id of the brake to 2-3 thousands more than the od of the end of the barrel. make sure there is no contour on the barrel were you will install it. Heat the brake up in a bearing heater or put it in a fry daddy. The id of the brake will expand as much as 7 thousands depending on the material. while it is hot slide it onto the od of the barrel. When it cools you will have a interference fit that will not come off unless you reheat it to remove it.

Thanks to all who replied...

1 - If I just filled the threads with Loctite 680 and screwed the brake on, any idea what effort it would take to remove it?

2 - Can anyone think of any other material that might work? Plastic steel, for example?

The threads are 9/16 X 24, probably about 3/4" long.

I am not interested in ever removing the brake, if I have to I will just cut the barrel.

quote:

If I just filled the threads with Loctite 680 and screwed the brake on, any idea what effort it would take to remove it?

Simply heating the component will break down the Loctite and it will come of easily. Not much heat is required - a bit over the boiling point of water. This is the design formulation of Loctite 680. Does the muzzle brake you have fit over the barrel? If it is loose, you could use some kind of filler material like wrapped paper, to hold it straight while the Loctite sets. As long as there is enough surface area it will hold fast. But Loctite takes a lot longer to set when large gaps are involved.