AAC 51T isn’t coming off

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[ARCHIVED THREAD] - AAC 51T isn’t coming off

Posted: 12/7/2018 1:28:19 PM EDT

I put this on several years ago, and went to take it off and it isn’t budging. I know I used Rockset. Any ideas? Heat? I was using an adjustable wrench, so I will get right sized wrench

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Posted: 12/7/2018 1:36:38 PM EDT

[#1]

Quoted:
I put this on several years ago, and went to take it off and it isn’t budging. I know I used Rockset. Any ideas? Heat? I was using an adjustable wrench, so I will get right sized wrench

https://www.AR15.Com/media/mediaFiles/324355/AB0E11CC-7D43-4A45-A64E-7B86D2FAED51_jpeg-763850.JPG

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Boiling water. Keep it in there for a good long while. Then simple torque.

Boiling water is key though.

Posted: 12/7/2018 1:40:33 PM EDT

[#2]

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Quoted:

Boiling water. Keep it in there for a good long while. Then simple torque.

Boiling water is key though.

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Any detrimental effects on the barrel doing that?

Posted: 12/7/2018 1:41:17 PM EDT

[#3]

The barrel should be supported in a vise before you attempt to remove the muzzle device.

Posted: 12/7/2018 1:41:56 PM EDT

[#4]

No detrimental effects.

Boiling water is the correct procedure.

Posted: 12/7/2018 1:47:03 PM EDT

[#5]

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The barrel should be supported in a vise before you attempt to remove the muzzle device.

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It is

Posted: 12/7/2018 1:52:10 PM EDT

[#6]

I've heard some people say hitting the brake with a hammer prior to soaking helps too, supposedly it causes the dried rocksett to fracture and weaken.

Posted: 12/7/2018 2:02:22 PM EDT

[#7]

Only weakness of rocksett is water over 160 F. Just dissolves it, no harm to the bbl.

Posted: 12/7/2018 2:06:08 PM EDT

[#8]

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Only weakness of rocksett is water over 160 F. Just dissolves it, no harm to the bbl.

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Will do, thanks guys.

Posted: 12/7/2018 4:15:15 PM EDT

[#9]

The wrench flats on those particular flash hiders are small and easily damaged if the brake is tight. This type of tool will help if you continue to have issues after following the above advice.

Note: I’m a machinist and make my own tools, so I don’t know if the first, less expensive option below fits your muzzle device.

https://www.thordsencustoms.com/3-pronged-flash-hider-wrench/

https://www.advanced-armament.com/BLACKOUT-Flash-Hider-Tool_p_477.html

Posted: 12/7/2018 6:07:03 PM EDT

[#10]

I just use the AAC flash hinder tool and torque to break the Rocksett.

Posted: 12/7/2018 7:55:48 PM EDT

[#11]

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It is

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Quoted:
The barrel should be supported in a vise before you attempt to remove the muzzle device.

It is

Not according to your picture.

Posted: 12/7/2018 9:05:58 PM EDT

[#12]

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Not according to your picture.

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It is. I have full workbench

Posted: 12/7/2018 11:48:36 PM EDT

[#13]

Are you directly clamped to the barrel? Using something like the Geissele reaction rod or BEV block can cause you to spin the barrel in the extension or sheer the pin. The 3 prong flash hider tool is a godsend, I soaked one, put the tool on the end of a hammer drill, off in 2 seconds.

Posted: 12/8/2018 4:21:43 AM EDT

[#14]

Get the flashhider tool. I have the AAC flashhiders on mine for can mounts, and experienced the same issue as you on my MK18 barrel. The flats are no bueno for torque, and I needed it because of the clearance on this rail, anyhow. I soaked it, clamped the barrel, and was still a tight mutha.

The tool is great gear.

Posted: 12/8/2018 5:28:21 AM EDT

[#15]

Water boils (sea level) at 212 F. Shoot 20 rounds through your AR15 pretty fast (not a mag dump, just a nice pace) and the barrel temps out near the muzzle will be around 280F. Maybe a bit more.

212 F won't hurt it a bit.

Posted: 12/8/2018 9:39:47 AM EDT

[#16]

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Water boils (sea level) at 212 F. Shoot 20 rounds through your AR15 pretty fast (not a mag dump, just a nice pace) and the barrel temps out near the muzzle will be around 280F. Maybe a bit more.

212 F won't hurt it a bit.

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It's not the heat it's the water that dissolves rockset.

Posted: 12/8/2018 11:52:40 AM EDT

[#17]

Quote History

Quoted:
Are you directly clamped to the barrel? Using something like the Geissele reaction rod or BEV block can cause you to spin the barrel in the extension or sheer the pin. The 3 prong flash hider tool is a godsend, I soaked one, put the tool on the end of a hammer drill, off in 2 seconds.

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It is a MUR upper and I can’t find the vise block that I used when I put this one together. I ordered the Midwest reaction rod. This gives me the excuse I needed. I am sure the reaction rod in combination with boiling water will work. I don’t want to get the AAC tool. 22mm wrench will work

Posted: 12/8/2018 12:14:22 PM EDT

[#18]

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It is a MUR upper and I can’t find the vise block that I used when I put this one together. I ordered the Midwest reaction rod. This gives me the excuse I needed. I am sure the reaction rod in combination with boiling water will work. I don’t want to get the AAC tool. 22mm wrench will work

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The Midwest Industries URR is a great tool, but using it to remove a potentially stuck muzzle device could pop the barrel loose from the barrel extension.

Barrel blocks are the best tool for muzzle device work.

Posted: 12/8/2018 12:30:57 PM EDT

[#19]

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The Midwest Industries URR is a great tool, but using it to remove a potentially stuck muzzle device could pop the barrel loose from the barrel extension.

Barrel blocks are the best tool for muzzle device work.

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If it gives me a hard time, I will let off

Posted: 12/8/2018 12:34:34 PM EDT

[#20]

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I've heard some people say hitting the brake with a hammer prior to soaking helps too, supposedly it causes the dried rocksett to fracture and weaken.

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I smack mine on the end with a rubber mallet and then take them off. Haven't had to soak one yet.

Posted: 12/8/2018 12:36:22 PM EDT

[#21]

I just went through this with a Surefire muzzle brake. First, I did not have a barrel block for my vise, and used a reaction rod. I do NOT recommend this - I'm buying a good block before I do this again. Nothing bad happened, but I could have used more force if I wasn't afraid of shearing the alignment pin or damaging the upper receiver or loosening the barrel extension.

Second, time is your friend. Be patient. Boiling water did not work after four attempts. I read on another forum to simply soak it for 24 - 48 hours, and it worked. Still stuck after 24 hours. Popped loose after 48.

I'm using less Rocksett from now on when I install these things

.

Posted: 12/8/2018 12:49:16 PM EDT

[#22]

Is there a barrel block that you all recommend? I just ordered this

https://www.amazon.com/NO-M-R-Purpose-Polymer-Groove/dp/B012BVM1E8/ref=mp_s_a_1_12?ie=UTF8&qid=1544287674&sr=8-12&pi=AC_SX236_SY340_QL65&keywords=barrel+block

Posted: 12/8/2018 1:04:23 PM EDT

[#23]

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Is there a barrel block that you all recommend? I just ordered this

https://www.amazon.com/NO-M-R-Purpose-Polymer-Groove/dp/B012BVM1E8/ref=mp_s_a_1_12?ie=UTF8&qid=1544287674&sr=8-12&pi=AC_SX236_SY340_QL65&keywords=barrel+block

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Those will probably work. These are my favorite. > Link.

You will likely have to remove your handguards to make space for the barrel blocks.

Posted: 12/8/2018 1:19:12 PM EDT

[#24]

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It's not the heat it's the water that dissolves rockset.

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I know, I thought the OP asked if hot water would hurt the barrel. I just wanted him to realize shooting it gets it far hotter than boiling water ever could.

Posted: 12/8/2018 1:25:46 PM EDT

[#25]

You'll just round off the flats with a wrench, get the three prong tool. Just my experience

Posted: 12/8/2018 1:30:09 PM EDT

[#26]

Attached File

Posted: 12/8/2018 1:39:58 PM EDT

[#27]

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Quoted:
Is there a barrel block that you all recommend? I just ordered this

https://www.amazon.com/NO-M-R-Purpose-Polymer-Groove/dp/B012BVM1E8/ref=mp_s_a_1_12?ie=UTF8&qid=1544287674&sr=8-12&pi=AC_SX236_SY340_QL65&keywords=barrel+block

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Those look fine! I have the NO MAR sets for barrels, and receivers

Posted: 12/8/2018 1:54:58 PM EDT

[#28]

Took a while to scrape of and clean off all the old Rockset. Threads are fine and all is good. Thanks for the boiling water tip

Posted: 12/8/2018 1:56:55 PM EDT

[#29]

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https://www.AR15.Com/media/mediaFiles/324355/047F69A4-03B6-473D-8E1F-4C14F95F9BE8_jpeg-765105.JPG

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And you somehow got it off, it's a miracle.

I'm still unclear on if you have the MI URR, or if you've only just ordered it? You must have it.

Posted: 12/8/2018 2:01:37 PM EDT

[#30]

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And you somehow got it off, it's a miracle.

I'm still unclear on if you have the MI URR, or if you've only just ordered it? You must have it.

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I ordered it. I made a barrel block out of scrap wood and drilled it out to 5/8. Then put friction tape in the channel

Posted: 12/8/2018 2:08:20 PM EDT

[#31]

Quote History

Quoted:
I just went through this with a Surefire muzzle brake. First, I did not have a barrel block for my vise, and used a reaction rod. I do NOT recommend this - I'm buying a good block before I do this again. Nothing bad happened, but I could have used more force if I wasn't afraid of shearing the alignment pin or damaging the upper receiver or loosening the barrel extension.

Second, time is your friend. Be patient. Boiling water did not work after four attempts. I read on another forum to simply soak it for 24 - 48 hours, and it worked. Still stuck after 24 hours. Popped loose after 48.

I'm using less Rocksett from now on when I install these things

.

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The only danger with a reaction rod is loosening the barrel extension from the barrel.

Think about how the RR interfaces with the barrel. There is no torque placed on the upper or index pin.

Posted: 12/8/2018 4:36:07 PM EDT

[#32]

Attached File

Posted: 12/9/2018 3:38:58 AM EDT

[#33]

Quote History

Quoted:
Took a while to scrape of and clean off all the old Rockset. Threads are fine and all is good. Thanks for the boiling water tip

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Probably going to use a tad less Rocksett next time, eh?

Posted: 12/9/2018 9:13:18 AM EDT

[#34]

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Probably going to use a tad less Rocksett next time, eh?

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Learn from my lesson? How dare you. Yeah, just one drop from here on out.

Posted: 12/9/2018 9:38:48 AM EDT

[#35]

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Learn from my lesson? How dare you. Yeah, just one drop from here on out.

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Quoted:

Probably going to use a tad less Rocksett next time, eh?

Learn from my lesson? How dare you. Yeah, just one drop from here on out.

How I use it, screw md on until only a couple of threads are showing then drop 1 dropplet and finish install.

Posted: 12/9/2018 11:41:17 AM EDT

[#36]

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How I use it, screw md on until only a couple of threads are showing then drop 1 dropplet and finish install.

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That’s what I did for new Sig Mount. I was able to salvage AAC Mount and that is on different rifle now. Shims were saved too

Posted: 12/9/2018 11:55:09 PM EDT

[#37]

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It is

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Quoted:
The barrel should be supported in a vise before you attempt to remove the muzzle device.

It is

The barrel and barrel only, close to the muzzle, not the upper receiver. I see you made a wood barrel block. Good solution. I just wrap a piece of scrap leather around the barrel just behind the muzzle and clamp it hard in the bench vise.

Posted: 12/10/2018 12:59:20 AM EDT

[#38]

I tell you something that works really good with a vise, conveyor belt pieces.

This shit is damn near indestructible and I got about 15 feet of it for nothing out of the company's trash.
Makes great bumpers for jack stands, floor jacks, or vise blocks.
Want a rubber base for some piece of equipment, liquid nail it on and it will take years to wear at all.
Used some as an air damn under the front of a SCCA '71 'vette and it lasted forever despite curbs and road crowns.

Posted: 12/10/2018 1:43:18 AM EDT

[#39]

Honestly letting the muzzle soak in cold water overnight usually does the trick. I’m sure boiling water would loosen it up quicker. Use the right tools and for Gods sake, don’t use a Reaction Rod.

Get a barrel vise! The Viper Bench Rest barrel vise is $75 well spent!