AR15.Com Archives
 *UPDATE* I need help getting my muzzle brake tight and indexed.
gargamel  [Member]
9/21/2010 1:19:57 PM
I threaded my Vepr AK down to properly fit a 14x1L muzzle device. I had a phanthom but I decided to go with a PWS FSC47. It threaded on as expected but it needs to be indexed. Unfortunatley, the Vepr has no dentent/ plunger pin to sit the FSC47. I am unable to give it a full turn to line up muzzle brake nice and tight as it if had the dentent lined up. The FSC47 is loose enough to move around. Will a crush washer / peel washer be my best bet to get it snug? If so, what size will you recommend? For a14x1 threaded barrel would a 5.56 or .308 size washer be the one I should go for?
gargamel  [Member]
9/21/2010 7:22:37 PM
Wow, what i assume would be a simple fix/question has not yielded any answers. I have called local gunshops and asked if either washer would work on a 14mm and they say that is an odd situation and they do not know. Is there at least one person out there who has been in this predicament?
eracer  [Team Member]
9/21/2010 7:29:28 PM
I've been in 'this predicament' with my AR. I can only assume that the 'fix' is the same....

Use a crush washer. Sand the concave side using 150-grit sandpaper until the washer is 1/8 turn from correctly indexed. Tighten until indexed (which should be about the recommended 20 ft.-lb.

(Now, let me say that the muzzle brake on my AKM is loose - and I hear it's supposed to be that way....unlike an AR.)
gargamel  [Member]
9/21/2010 8:49:51 PM
I was considering a ar-15 crush washer but some guy at the shop said it was a bit too small. It is cheap to DIY the crush washer as you stated.

Is you muzzle break loose but held in by the plunger that is in your front sight base? My AK does not have it so that is why i do not want to come off, hence I need a way to tighten it down properly and indexed at the same time.
ak47mays  [Team Member]
9/21/2010 9:14:47 PM
i drilled and put my own detent pin in my mak-90. if you take your time and think it through it will turn out fine.
gargamel  [Member]
9/21/2010 9:25:55 PM
Originally Posted By ak47mays:
i drilled and put my own detent pin in my mak-90. if you take your time and think it through it will turn out fine.


Hmm...I still plan to explore a washer alternative but how difficult was to drill? W hat else did you have to do? Is this waht is needed:
From K-VAR

What drill bits were needed? I am just wondering how you did it but I doubt I have the experience to do this myself.

Anyone still have rigged an ar-15 crush washer to work, please let me know.

I only seen them on the net but, I wonder if those 14mm drain plug washers used on cars will work and not be too wide......
uscombatdiver  [Member]
9/21/2010 10:46:16 PM
It is not that hard, if you can drill some holes you should be able to install the pin. The key is taking your time and doing it right as though you only have one chance to do it. As for washers you could do that. I have done various other things when a pin was not an option from using the cleaning rod on a pistol build to index the muzzle brake to simply silver soldering it in place. The questions you need to ask yourself is apart from having this muzzle brake, what else do you want. Even industrial strength lock-tite may be an answer depending on what you want.
gargamel  [Member]
9/21/2010 11:05:25 PM
Meh. I just went to Autozone and bought a cheap copper 14mm washer as I mentioned above. It fit perfect over the thread although it is obvious I have a copper washer there and it does look cheap. I would say it is about hand tight (more like limp wrist hand tight).

With no washer, I am able to get 1/2 a turn shy from a full turn to put the detent cut facing up where the plunger would normally go. I take it having it "indexed" like this will throw off the FSC47? The cuts on the brake are facing sideways and not up and down.

If this will be a no go, I am wondering if filing the bottom of the actualy flash hider a bit to offer a little more give would allow me to get the 1/2 turn needed. Looking inside the brake, there is enough threading to allow this to happen. Does this crazy idea seem actually a good idea? Looks like it will work and there is enough room that will not mess with the threads.
ak47mays  [Team Member]
9/22/2010 4:28:09 PM
Originally Posted By gargamel:
Originally Posted By ak47mays:
i drilled and put my own detent pin in my mak-90. if you take your time and think it through it will turn out fine.


Hmm...I still plan to explore a washer alternative but how difficult was to drill? W hat else did you have to do? Is this waht is needed:
From K-VAR

What drill bits were needed? I am just wondering how you did it but I doubt I have the experience to do this myself.

Anyone still have rigged an ar-15 crush washer to work, please let me know.

I only seen them on the net but, I wonder if those 14mm drain plug washers used on cars will work and not be too wide......


yes sir, that will do it. i'm no gunsmith either so i can't give you any real technical advice. i just found a bit slightly larger than the detent pin. then i put it in the drill press and kinda eyeballed where it needed to go to barely make the notch in the detent catch the front pin in the site block. then i drilled that puppy. maybe someone else can give you more precise measurements. good luck w/ it how ever you end up doing it.
gargamel  [Member]
9/22/2010 7:44:12 PM
I took some time with a flat file and took the bottom of the brake and took off just enough to where it will index like it should. I used my ar-15 armorer's wrench to get it nice and snug. I doubt it wil move now. Blends in with the barrel and much better then a make-shift washer.

Now, should I grease the threads or use lock tite? I read Dinzag recommends using plumber's teflon tape. What do you guys recommend on this last step?