AR15.Com Archives
 How to remove an AR-10 Pinned and welded Muzzle Break: The Split and Pry Method!
Quarterbore  [Team Member]
9/13/2004 10:49:02 PM
To my knowledge there is three general ways to remove these breaks. There is the ar15.com/forums/topic.html?b=2&f=27&t=143510]drill and unscrew] method (which I might had done if I had seen that thread before I started tonight), the lathe method (I have the lathe but no live center yet), and the split and pry method. I had seen the split and pry method done on the forums back in the 90's (1997-1998?) and I decided to do that method as I knew I could control the dremel tool pretty well....

Following are the steps:


1. Verify your barrel is a pin and welded break... like above.


2. Remove the gas tube


3. Gas tube gone.


4. Mount the barrel in a set of barrel blocks and crank her down with the welded pin up.


5. Ready to start cutting


6. Lengthwise cut right through the weld.


7. Grind down until you start seeing signs of the threads... go SLOW when you get close!


8. This was close... I went until I could see a regular pattern in the break indicating the threads were close.


9. Rotate the barrel 180-deg and do the top of the barrel next.


10. After I got down to the threads again I used a chisel and tried to split the break... didn't work real well


11. More spreading...


12. Used the anvil portion of the vise and split that bitch off there!


13. Once the break was split, she twisted right off the barrel by hand.


14. No damage to the threads except for where the pin was located.


15. The crown had no damage!


16. Gem-Tech TPR-S Bi-Lock mount


17. Threading the Bi-Lock onto the barrel


18. My AR-10 is ready for a Gem-Tech TPR-S... too bad I am flat broke and baddly in debt!

Tools Required:

1. Vise
2. Barrel Blocks
3. Dremmel tool with Fiberglas cutting wheels
4. Good Sized hammer
5. A couple chisels

This took about an hour to do.... Hope this helps.... I hope to use the lathe with the removal of my next break!

Paid Advertisement
--
Corporal_Chaos  [Team Member]
9/13/2004 10:59:06 PM
Beautiful work. Do you know if the Bi-Lock affects accuracy any differently than threads?
SHIVAN  [Team Member]
9/13/2004 11:04:17 PM
Is that pin damage close to through the barrel?
Quarterbore  [Team Member]
9/13/2004 11:10:23 PM
Do you mean affects accuracy in relation to a silencer mounted to the bi-loc as opposed to mounting the can on the threads? My understanding is that the Bi-lock is stable and prevents baffel strikes. I am going with the Bi-Lock system as I will be able to use the TPR-S with my AR-15 (rifles and pistol in 300 Whisper), AR-10s, FALs, and Rem 700 Bolt guns. By using the bi-lock I don't risk damaging the threads as much when I move the can from system to system...

Now, if you meant accuracy in general, the Bi-Lock is classified as a flash hider by the BATFE and I wouldn't see any reason it would affect things any worse then the blast enhancer I just removed. Also, I always have the option of replacing the blast enhancer if I want but this time it will not be welded on!
Quarterbore  [Team Member]
9/13/2004 11:12:20 PM

Originally Posted By SHIVAN:
Is that pin damage close to through the barrel?



No, the photos don't really look like the weapon... this is a minor hole that is perhaps 3-4 times the depth of the threads... nothing to worry about!
uglygun  [Member]
9/13/2004 11:13:18 PM
Seems there are some differences in how the brakes were installed...

Compare the brake in the above picture to the way the pin forms a secant chord across the threads of my barrel.


Couple detailed pictures of the headache I went through with my muzzle brake, I only had access to a grinding wheel though it would appear now that it wasn't a bad alternative now that I see how big my pin was and how much of the rifling it engaged. Once I had the pin out, I spun the brake off the threads and then chased them with a 5/8x24 hex die. Not sure how much easier it would have been with a dremel but I am positive that I didn't nick the threads of the barrel while grinding, was pretty careful while going to town on the muzzle brake.

I wish I had a properly indexed 3 port brake to keep around for some instances where I want that sort of blast enhancing and recoil reducing property.

As it stands now though, I really kinda like the way my Vortex rings like a tuning fork with each shot. That sucker is LOUD, you can hear it going off over the pogo stick sound of the noise of the buffer/spring in the stock.

www.ar15.com/forums/topic.html?b=3&f=62&t=198880
SP10  [Team Member]
9/13/2004 11:15:45 PM
Hmmmm, I wonder how many new barrels ArmaLite will be A)selling, B) repairing for over-eager *WECSOGer's and their humming dremels of destruction

Nice job, Q-bore! Another AR-10 in the form it COULD have been in many years ago!




* Wile. E. Coyote School Of Gunsmithing for you non-FAL board folks
uglygun  [Member]
9/13/2004 11:25:34 PM
Yeah, no doubt huh?


I was expecting a pin that went from the 6 o'clock position being driven towards the 12 o'clock position for an engagement 90 degrees perpendicular with the threads. Fortunately I saw the pin beginning to change it's profile as I ground the surface down, a slight hairline split between muzzle brake and pin showing me an outline and that suggested the pin being placed on a secant chord against the threads.

Going slow and being observant definitely pays off.
Quarterbore  [Team Member]
9/13/2004 11:33:04 PM

Originally Posted By uglygun:
Yeah, no doubt huh?

Going slow and being observant definitely pays off.



Well, I have more control over this then had I dug out the grinder and fired up the air compressor! With the dremmel you have some pretty fine control over how much material you are removing and the metal shows the threads before you really brake through and cut up the threads!

True however... slow and careful is better then rushing... unless you don't mind buying a new barrel when you are done!
uglygun  [Member]
9/13/2004 11:37:09 PM
Oh I agree, a dremel is a different critter than that of an air grinder.

If I had a dremel I too would have probably gone that route. Hell I would have probably tried to carefully carve out the portion of the pin so that it could be driven out so that I could remove the brake without grinding it to hell like I did.


It's almost possible that I can remove my brake if I were to get a tap and run it down the threads, then have the thing spun on a lathe to clean up the look of the brake a bit. It's definitely lookin pretty ugly right now as it is, bit better shape than yours though
Corporal_Chaos  [Team Member]
9/13/2004 11:37:58 PM
What is required to torque the Bi-Lock onto the barrel? I'm really thinking about going with a thrad mounted version since I'll be getting the HALO to cover the 5.56 stuff, but I just can't seem to decide.
Quarterbore  [Team Member]
9/13/2004 11:46:10 PM
Honestly, I have it hand tightened for now... Gem-Tech does have specs for the Bi-Lock mounting and I happen to have them on-line...

quarterbore.com/images/tprs-bilock-dir-1.jpg

quarterbore.com/images/tprs-bilock-dir-2.jpg

quarterbore.com/images/tprs-bilock-dir-3.jpg

quarterbore.com/images/tprs-bilock-dir-4.jpg

I need to make some type of wrench to tighten this but I need to get my FF Rail tube on this AR-10 (From SniperX) before I get things all loc-tited down and torqued up! I just need an AR-10 free float retaining ring to finish this build-conversion!
Corporal_Chaos  [Team Member]
9/13/2004 11:49:38 PM
Awesome. Since you'll probably be able to afford the TPR-S before me, be sure to post a range report when you get it!
Rossi  [Member]
9/14/2004 12:59:15 AM
Great job with the old brake removal and pictures!

I am still stuck with mine. I have the T model, which uses the SS barrel and brake.

I simply cannot see any sigh of a pin or weld on that brake. I've even checked all perimeter with a magnifying glass and cannot see anything but a very smooth surface...

I imagine that if my model was the new one I would clearly see the non welded pin. However, it's not there, which makes me think I have the older (welded) version.

Anybody also has a T model and could clearly find the weld sopt?

Thanks!

P.S. Another question. Anybody documenting that the change was done after the sunset, such as using newspaper backgrounds or simply change the stuff?


Combat_Jack  [Team Member]
9/14/2004 1:13:06 AM
Don't bother documenting your guns unless another ban is coming, in which case you will have plenty of time to prepare.
Slash  [Team Member]
9/14/2004 9:20:25 AM

Originally Posted By Rossi:
I have the T model, which uses the SS barrel and brake.

I simply cannot see any sigh of a pin or weld on that brake. I've even checked all perimeter with a magnifying glass and cannot see anything but a very smooth surface...

I imagine that if my model was the new one I would clearly see the non welded pin. However, it's not there, which makes me think I have the older (welded) version.

Anybody also has a T model and could clearly find the weld sopt?



Yours is likely just like the one QB shows above. I have an M15T S/S that I removed the brake from last year. The pin was VERY well hidden, on S/S guns you can barely see it at all. Look at the bottom (six o'clock) of your brake, and you should see an area about 5/16" diameter that is a slightly different shade of silver. That is the weld, and the pin is right there.



Corporal_Chaos  [Team Member]
9/14/2004 8:08:00 PM

Originally Posted By Rossi:
Great job with the old brake removal and pictures!

I am still stuck with mine. I have the T model, which uses the SS barrel and brake.

I simply cannot see any sigh of a pin or weld on that brake. I've even checked all perimeter with a magnifying glass and cannot see anything but a very smooth surface...

I imagine that if my model was the new one I would clearly see the non welded pin. However, it's not there, which makes me think I have the older (welded) version.

Anybody also has a T model and could clearly find the weld sopt?

Thanks!

P.S. Another question. Anybody documenting that the change was done after the sunset, such as using newspaper backgrounds or simply change the stuff?





This is still the United States. Burden of proof is on the prosecution, I don't give a shit what the ATF says. If you run into anyone that disagrees, show 'em the constitution.
bjwar10  [Member]
9/15/2004 11:16:46 AM

Did your pin go to the ejection port side as well?
sniperx  [Dealer]
9/15/2004 11:22:06 AM
Rossi,

I have a ss T as well and I can see the outline of the weld if you hold it just right in the light.

I have not decided yet to remove it though.
Quarterbore  [Team Member]
9/15/2004 12:24:47 PM

Originally Posted By bjwar10:
Did your pin go to the ejection port side as well?



Major Edit.. what was I thinking???

No... it looks to me like the break was drilled and a notch was cut in the threads... the break was then threaded onto the barrel. The barrel WAS THEN DRILLED AT ABOUT A 45-DEG ANGLE and the pin as dropped into the slot WAS INSTALLED and welded over...

CAPS is the Update! Also, when I split my Blast Enhancer I actually cut through the pin and didn't know it! Now, I wasn't looking for it either but the cut off wheel didn't really show where it was...
sniperx  [Dealer]
9/15/2004 12:30:41 PM
I would think that the brake is threaded on and then a hole drilled but not through (blind)
pin installed and then welded over.
bjwar10  [Member]
9/15/2004 1:07:16 PM

I was not very clear in my question...the pin although it is in the 6 o'clock position, does not meet the threads at a 90 degree angle. It appears a 90 degree cut is made i n the pin and the pin actually contacts the threads at either the 3 o'clock or 9 o'clock position...9 o'clock being the ejection port side. Uglygun describes it well in another post. I'm curious if the angle cut in the pin is always angled towards the same side.
Quarterbore  [Team Member]
9/15/2004 3:29:26 PM

Originally Posted By bjwar10:
I was not very clear in my question...the pin although it is in the 6 o'clock position, does not meet the threads at a 90 degree angle. It appears a 90 degree cut is made i n the pin and the pin actually contacts the threads at either the 3 o'clock or 9 o'clock position...9 o'clock being the ejection port side. Uglygun describes it well in another post. I'm curious if the angle cut in the pin is always angled towards the same side.



You are still not clear...

Did you see this www.aoe.vt.edu/~jchock/Armalite%20MB%20removal.pdf...? It is another method!
bjwar10  [Member]
9/15/2004 5:15:40 PM

I hope this works...if not check out the pics in this thread.

ar15.com/forums/topic.html?b=3&f=62&t=198880



Some of the pictures posted in other parts of the forum lead me to believe that the pin would be centered to engage the threads with a 90 degree orientation to the threads driven in from the 6 o'clock position of the muzzle device.

Once I got to removing said blast enhancer it became apparent that the pin takes off at an angle to form a chord or secant across the threads of the barrel. As I was grinding down into the blast enhancer you could see a thin outline of the pin and as you went deeper the pin changed from a more rounded shape to an oval shape, suggesting that the pin was set on angle.

If I hadn't paid careful attention to what I was doing and could clearly see the offending pin, it's possible I would have ground down into the threads of the barrel.

Here's some high res pics of said muzzle device and the barrel. My pin was driven in from the bottom and it took off towards the ejection port side of the rifle, I had no way of knowing in advance which direction the pin took off against the threads so I did some exploratory grinding to try to find out what direction the pin was going.

I ordered a custom hex die specifically for this job because I figured the threads would be pretty ugly once the device was removed, sure enough they weren't the prettiest thing you ever saw. What is shown below is what the threads look like after chasing the threads with the hex die, plenty clean now.




Looks like the picture is not going to post...please check out the thread.

THanks
uglygun  [Member]
9/15/2004 5:19:29 PM
Looking at the pictures of Quarterbore's threads and how the pin engaged the threads, it appears to be a different process than how the pin engaged the threads on my brake.


The pin on my brake went across a wider portion of the threads and covered a longer distance/chord through the brake, viewing the barrel by looking directly down on where the spot weld once existed, the area of contact with the threads of the barrel was rotated over towards the ejection port side of the rifle by a fair margin.

Looking at Quarterbore's pictures it appears that the thread engagement exists almost directly underneath the spot where the spot weld once was, is this true Quarterbore? The chord that is formed by the way the pin is driven in, seems like it is parallel to an imaginary horizontal line through the 3o'clock and 9o'clock positions of the barrel, the actual engagement point or tangent formed by the pin is right at 6o'clock position.



With my brake, the actual engagement is rotated over so that the tangent point where the pin contacts, that line would be parallel to a line formed between the 7 o'clock and 1 o'clock positions on the barrel if viewing the engagement as one would shoot the rifle(or 5o'clock and 11o'clock if we are viewing the engagement as looking down the barrel from the muzzle).


Of note, one thing I noticed is that Quarterbore has a 2 port brake while mine was a 3 port brake. Perhaps a change in technique used to pin these brakes onto the barrel?
bjwar10  [Member]
9/15/2004 5:50:24 PM

Thanks uglygun. I didn't notice that yours was a three-port. I have a two port. Looks like I'll be trying the split and pry method first.

God, please guide my hands as to not mess anything up.
bjwar10  [Member]
9/15/2004 5:58:34 PM

So what's the deal on silencers? Is it the same as class III?

$200 + paperwork + 6month fed processing

Does the $750 for the quick detach TPR-S include a bilock mount or is that $85 extra?

Thanks
Corporal_Chaos  [Team Member]
9/15/2004 6:25:32 PM

Originally Posted By bjwar10:
So what's the deal on silencers? Is it the same as class III?

$200 + paperwork + 6month fed processing

Does the $750 for the quick detach TPR-S include a bilock mount or is that $85 extra?

Thanks



That's all pretty accurate except the 6 month wait is not standard. It could be two months, it could be a year or more, or anything in between. Corporate transfers move faster than individual transfers. If you do an individual transfer, you will need duplicate copies of finger print cards and passport photos, plus a chief law enforcement officer sign off. These three items are not necessary for a corporate transfer.

I'm not positive but I think Gem-Tech includes one bi-lock with their quick detach bi-lock models.
jchock  [Member]
9/15/2004 6:33:28 PM

Originally Posted By bjwar10:
I'm not positive but I think Gem-Tech includes one bi-lock with their quick detach bi-lock models.



They do. Its one of the "new" model thread at muzzle/front bilocks. The older style muzzle brake/fh version was found to have accuracy issues, and is no longer manufactured. A bi-lock TPR-S comes with one bilock... If you're lucky, your dealer will let you have the bilock early so you can send it and the barrel to Gem-Tech for installation, thus when your F4 comes back, you can go from the dealer straight to the range.

--Jeff Chock
Quarterbore  [Team Member]
9/15/2004 11:55:06 PM

Originally Posted By bjwar10:
I was not very clear in my question...the pin although it is in the 6 o'clock position, does not meet the threads at a 90 degree angle. It appears a 90 degree cut is made i n the pin and the pin actually contacts the threads at either the 3 o'clock or 9 o'clock position...9 o'clock being the ejection port side. Uglygun describes it well in another post. I'm curious if the angle cut in the pin is always angled towards the same side.



I understand now... Mine angles in from bottom to top in the pic that folows...



IE: 6:00 to 3:00 as you stand at the butt....
Jimbeaux  [Member]
9/15/2004 11:55:35 PM
Like uglygun, my 3-slot A2-C blind pin went accross the bottom of the threads further than the pictured example. Looking at the brake from the muzzle, mine had the pin running from the 7 o'clock over to about the 4-or-5 o'clock. I used a little different technique. With a 1/4 inch carbide plain rotary file chucked into a drill press, I placed the barrel in a block on a machinist vise and milled across the bottom of the brake adjusting the angle and depth to cut the blind pin in half lengthwise. I them made a slightly deeper cut just to the blind side of the blind pin to get a surface to drift it out. It came out very easy. A2 birdcage and "standard" sight base ordered from Armalite this AM. Still no source for peel washers to time it--but I'll come up with something. As it is, I have 3 "standard" features now with the threaded barrel. Heads up, the breke is screwed on very tight! Many thanks to the early posters for sharing what you had and how you got the blast enhancers off--I've been waiting years to get that thing off my favoirite semi!
Quarterbore  [Team Member]
9/15/2004 11:58:25 PM

Originally Posted By jchock:

Originally Posted By bjwar10:
I'm not positive but I think Gem-Tech includes one bi-lock with their quick detach bi-lock models.



They do. Its one of the "new" model thread at muzzle/front bilocks. The older style muzzle brake/fh version was found to have accuracy issues, and is no longer manufactured. A bi-lock TPR-S comes with one bilock... If you're lucky, your dealer will let you have the bilock early so you can send it and the barrel to Gem-Tech for installation, thus when your F4 comes back, you can go from the dealer straight to the range.

--Jeff Chock



+1 See the directions as linked on page 1... They still make and sell this style Bi-Lock but the other style is the style they recommend. When I talked with Gem-Tech they indicated that these will still work fine and I bought two of these... One for my 300 Whipser and this one for the AR-10! Mine is the Muzzle Brake/Flash Hider version as Jeff Describes but the directions I posted earlier shows what is needed for the other style to mount!

Rossi  [Member]
9/16/2004 9:33:55 PM

Originally Posted By sniperx:
Rossi,

I have a ss T as well and I can see the outline of the weld if you hold it just right in the light.

I have not decided yet to remove it though.




I'll try the light trick. Thanks for the hint. So far the only thing I found, using a magnifier, was a "shadow" of a round scratch, which is not conclusive.

I've already received Armalite's FH. Will work on it during the weekend. Its fisnish does not match the barrel semi-polished finish. It's more like the blasted finish of the front gas block. Not bad, but would look better if it matched the barrel finish like the brake.
bjwar10  [Member]
9/18/2004 7:50:17 AM

IT IS GONE!!!

It popped last night...what a sweet sound. Threaded barrels look awesome. I hate to cover them up.

Quick question...I tried to thread my vortex on and it would only go about 1/4 turn before it met some resistence. The threads look good but I am afraid of cross-threading and damaging the threads.

Should it thread on smoothly? SHould I have the threads cleaned up (even thought they look fine) and if so who can do that? Machine shop? Gunsmith?

I'm so close.

Thanks for all the pics.
Slash  [Team Member]
9/18/2004 2:27:37 PM

Originally Posted By bjwar10:
IT IS GONE!!!

It popped last night...what a sweet sound. Threaded barrels look awesome. I hate to cover them up.

Quick question...I tried to thread my vortex on and it would only go about 1/4 turn before it met some resistence. The threads look good but I am afraid of cross-threading and damaging the threads.

Should it thread on smoothly?

YES


Should I have the threads cleaned up (even thought they look fine) and if so who can do that? Machine shop? Gunsmith?
Either one, or order a 5/8-24 die from MSC or a local supply house.

bjwar10  [Member]
9/20/2004 6:35:26 AM

I'm not trying to beat a dead horse but...

I've got the 5/8 die. How do I insure that it will follow the existing threads and not try to cut totally new ones? I've never threaded or cleaned up existing threads before. Should I let someone with some experience do it or is it pretty easy?

Thanks
sniperx  [Dealer]
11/17/2004 4:19:26 PM
tag for bump
Quarterbore  [Team Member]
11/17/2004 4:36:51 PM

Originally Posted By bjwar10:
I'm not trying to beat a dead horse but...

I've got the 5/8 die. How do I insure that it will follow the existing threads and not try to cut totally new ones? I've never threaded or cleaned up existing threads before. Should I let someone with some experience do it or is it pretty easy?

Thanks



Honestly, if your threads don't look bad and you can thread a FH on I wouldn't mess with it.

If the threads are pretty bad, you still should be able to slowely and carefully thread the tap onto the threads without cross threading things. Just don't do more then a turn or two before you confirm that you are not cross threading... Then again, by now you have probably already done this, huh?
QuietShootr  [Team Member]
11/17/2004 4:37:29 PM
You don't have another Bi-Lock do you?
Quarterbore  [Team Member]
11/17/2004 4:42:17 PM

Originally Posted By QuietShootr:
You don't have another Bi-Lock do you?



Do you mean other then the one I am using on the AR-10 and my 300 Whisper pistol... no, those are the only two I own...


quarterbore.com/ar15m16/postbanar15pistol.htm

Still, you can call Gem-Tech as when I ordered these they indicated that they still do limited runs of this older style so perhaps they can help you out! Seems to me there should be a solid demand for a run of these now that we have threaded barrels again!
Paid Advertisement
--