OOPS! I broke my AR-10


Badger Arms
October 5, 2004, 12:02 AM
I was carrying my AR-10 to the safe tonight and I tripped and fell on a Dremmel tool! It was a horrible accident. All happened in slow motion. Sparks and metal were flying, grinding was heard, and suddenly it was all over. When the fiberglass dust and acrid smell cleared, my muzzle was a naked tangle of threads. And to think, it was a felony just a few weeks ago. Pity, now I have to fix it. That muzzle brake isn't serviceable anymore... what to do... what to do? :uhoh:


Seriously, I simply gripped the brake in a vice and went to town on the single hole at the bottom of the brake. When I got down as far as I felt comfortable, I took a punch and -- working striking in a counter-clockwise direction -- pounded what remained of the pin out. There were threads underneath. Now I have to order the flash suppressor from Armalite. I look forward to quieter range trips and a more aesthetically appealing rifle.

BTW, that's not heat discoloration on the barrel, I cleaned it with brake cleaner to get the carmel-colored grease off of it.

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October 5, 2004, 12:32 AM
:cuss: dremel tools with no external safeties!

Harry Tuttle
October 5, 2004, 12:33 AM
dats not broke
dats fixed!


Badger Arms
October 5, 2004, 12:37 AM
Well, the brake is broke. Broken brake, broken pin, fixed gun you could say.

Sylvilagus Aquaticus
October 6, 2004, 12:27 AM
Those threads look as if they'd clean up with a little work, though.

Glad you're replacing that noisemaker with a quality flash hider.


October 6, 2004, 08:23 AM
Hmm, threaded barrel, 308, $200 ATF taxation (without representation, but I digress)

I don't know if they make subsonic 308, and I also don't know if anything fancy has to be done to get an AR-10 to cycle with a reduced 308 cartridge (if they make such a thing).

What would be neat is to have a threaded flash hider, that can go on and off, and a sound supressor too. I would be real curious about the ballistics of such a caliber supressed. Anybody here done this before?

Inquiring minds want to know...

Badger Arms
October 6, 2004, 12:18 PM
Well, suppressing the muzzle report of a .308 is fine. Most of the larger suppressor manufacturers make a versioni that is strong enough. The problem is with the supersonic crack. You can use subsonic ammo, but then you might as well use the AR-15 platform and the 300 Whisper since you'll have to reload anyway. If you want a gun that will shoot full-power 308 AND subsonic, you can do that, I suppose, but the greater volume of the .308 make it less efficient as a reduced load with a heavy bullet.

If I'm going to suppress anything, I'm just going to put-up with the supersonic crack. My reasoning is that if I can shoot without ear muffs, it's fine by me.

Badger Arms
October 6, 2004, 12:19 PM
BTW: Armalite said they had the Flash Suppressors in stock, but didn't have the crush washers needed to index them. I was given two-three weeks as a time when they'd have them. If I need to use the rifle, the Brake still works fine if it looks a little rat-eaten.

October 6, 2004, 07:56 PM
I know everyone likes the 300 for supression. And obviously who cares about 308 vs .300 when they both only move at 1040fps or less. Go with the cheaper system ($600 for a decent Oly Arms in 300)

I guess I was thinking it would kill two birds with one stone, have an upper that can shoot long range, and go quiet too when you want.

I STILL haven't decided what caliber to use for my big bore, go quiet AR.

Now that I think about it too, I can't imagine you can shoot too much supersonic through a .308 can and have it stay working. I imagine it would kill the deadening material and gum up the works pretty quick. Anybody here have any experience with supressors? I've not studied them in quite sometime.

October 6, 2004, 08:28 PM
From the innards I've seen of the modern ones, there *is* no deadening material -- just a series of steel baffles with holes drilled in assorted places. The really cool thing is how some of 'em work -- the placement and angle of the baffles is such that the sound of the shot is canceled out via harmonic interference, or at last that's what the patent docs say.

Pretty darn swoopy. :)

Sylvilagus Aquaticus
October 6, 2004, 08:42 PM
Yeah, wire mesh baffles and rubber wipes are 'old tech'. Stainless/titanium machined baffles are the way to go. Dip it in solvent or disassemble it and dust it out every few hundred rounds and it'll do fine.

As for the crush washers, have you checked your local well-stocked hardware store for a suitable workaround?


Badger Arms
October 6, 2004, 09:28 PM
While I have a local hardware store, I don't think anybody would EVER call them well-stocked. Besides, I waited 10 years, what's three weeks!?

I've looked at them 'Reflex" Suppressors. That would be cool if I could find one in the US. They only stick out two or three inches beyond the muzzle... not too much more than a standard flash suppressor. The body of the suppressor telescopes back over the barrel. Not as efficient as modern ones, but just fine for supersonic bullets methinks.

October 6, 2004, 11:18 PM
I removed my old 3 port brake a few weeks back and the pin was difficult to locate, some threads on AR15.com indicated that the pin would be contacting the bottom of the threads from the bottom of the brake and I figured the centerline of the pin would be lined with the vertical centerline of the barrel.

As I started grinding, to my surprise I found the dumb pin actually took off to form a chord/secant with the threads of the barrel. I could just barely make out the pin as I was grinding away and fortunately I was able to note that it was becoming more oval in shape which hinted it was going one direction or the other.

Unfortunately my brake is rather ugly now and not something I think I can clean up to reuse if I should choose to have a muzzle brake on the rifle at some point down the road. I'll have to order another one and time it to this rifle.

Here's a pic of my brake, I had to grind in both directions to find out what direction the pin was going. I was darn tootin careful to not grind down into the threads and I was succesful in my goal of not damaging the threads.

I chased my threads with a 5/8x24 hex die and they cleaned up pretty darn nice. A vortex now resides on the AR10 and I have the option of choosing to suppress the flash or the option to suppress recoil once I get a new muzzle brake, nice to have that option....


Badger Arms
October 7, 2004, 02:54 AM
Where'd you get the Vortex? Me, I'd rather see the phantom with the ports closed at the bottom. I like shooting prone.

October 7, 2004, 02:06 PM
It's their 308 vortex listed on the Smith Enterprises site, I got mine from G&R Tactical and was their last in inventory.

Funny thing is now I can hear a tuning fork "TWANG" whenever I fire this rifle, even over the sound of the pogo stick buffer spring sound.

I was hoping for a Phantom like the older 4 port suppressor with knarly teeth on the front of it but the 30cal models aren't out yet, YHM might be making some one of these days though so keep an eye out.

October 7, 2004, 03:17 PM
You can also pick up a CETME or HK flash suppressor and chase the threads with a 5/8-24 tap and it'll fit right on. I had a couple of CETME brakes laying around and the Tap cost me $13 from McMaster Carr.

My Armalite brake looked just like Uglyguns when I got through with it. There was a whole lotta' grindin' goin' on.

Badger Arms
October 7, 2004, 08:23 PM
I did have to follow the pin around the side, but I had seen somebody elses picture and knew that it went up and to the right side of the barrel. As long as you can see the outline of the pin and keep following it, you'll do fine. HAven't seen a picture of mangled threads yet.

BTW, I didnt' chase my threads at all. Why do they need to be chased? I dont' want to remove metal if the brake that Armalite is giving me is going to fit... I think that would be counterproductive, don't you?

October 7, 2004, 08:37 PM
I went to try to install my Vortex flash suppressor and it would spin on only about 1/4 of the total distance needed before resistance was encountered.

For some reason the threads on the barrel seem to be a little over diameter, not sure of the reason but the Vortex needs to be installed with the suppressor bottomed out against the muzzle. After cleaning up the threads with a hex die the Vortex installed cleanly and easily.

Badger Arms
October 7, 2004, 10:25 PM
Thanks for the advice. I already have the die, but I'm going to leave the Armalite Flash Suppressor on when I get it. I'm holding out for the Phantom Flash Suppressor with the closed bottom if they make it that way. If I see one and the threads match, I might get it. Either that or a good suppressor!

October 8, 2004, 01:41 PM
A vortex now resides on the AR10I'm putting Vortex devices on all of my rifles AR, FAL, Savage 10FP.

I will buy a single Fisher Enterprises sound suppressor which is designed to clamp onto the rear groove on the Vortex.


Badger Arms
November 20, 2004, 04:10 AM
Well, I finally got the time to install my flash suppressor. Instead of using the ill-fitting compression washer that Armalite sent me, I decided to just trim the rear of the brake until it indexed right... just a little canted to the right to compensate for my right shouldered twist. Here's the final product. I ended up taking off about .035" which was a great deal more than I should have. I overshot the first try and had to take off another thread worth. Luckilly, the Flash Suppressor was deep enough to accomodate this. Heck, if I messed it up it was less than $25 delivered so I could have just bought a new one.


November 20, 2004, 04:24 AM
I love blued steel with weird holes in it. :D

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