View Full Version : Barrel Nut Removal Tips?
medicman816
11-23-18, 15:43
I've searched and can't seem to find an answer. I have a BCM factory upper that I would like to remove the GI barrel nut from in order to install an aftermarket rail. I have the Brownells brand barrel extension tool and a GI armorers wrench, have applied penetrating oil and heat, and can not seem to get this to budge. I've put most of my near 200# gorilla strength behind it and still a no-go. Is there a trick to this? What tricks have worked in the past? At what point does one just move on to the dreaded dremil tool for a more violent removal? Thanks in advance.
The BCM barrel nuts are torqued on by Zeus himself.
I used this wrench in the link and applied slow even pressure then it finally broke free.
I was using the GI armors wrench too, but kept breaking teeth off of the barrel nut. This wrench grips multiple points all the way around and really helps.
https://www.brownells.com/gunsmith-tools-supplies/rifle-tools/wrenches/ar-15-m16-barrel-nut-wrench-prod27412.aspx
There is a good chance that you are going to shear the indexing pin and damage the indexing pin notch in the upper receiver using the Brownells barrel extension tool to remove a stuck barrel nut.
Put your barreled upper in the freezer for an hour, then take it out and heat up just the barrel nut with a torch, then put your upper in the vise in a set of clam shell upper receiver vise blocks.
Stick this in the upper/barrel extension for added support. > https://www.midwestindustriesinc.com/MI-Upper-Receiver-Rod-p/mi-urr.htm
Then attempt loosening with a good quality barrel nut wrench... I prefer this one, but the one from PRI is good too. > https://www.2uniquellc.com/product-page/ar15-m16-barrel-nut-wrench
medicman816
11-23-18, 17:09
Thanks for the help so far...
Im noticing a white substance around the threads, which I would hope is anti-seize. Im going to try the differential cooling now. Had it up over 350 with the heat gun without success. Is there a theoretical max heat?
7075T6 can be heated to 250 degrees for no more than a total time of 30 minutes without negatively impacting the heat treat.
I think BCM used to use a white lithium type grease on the upper receiver threads, though I'm not sure if they still use the same stuff anymore.
It might have taken to long to heat up with the heat gun, the aluminum upper will react faster to temperature change than the steel barrel nut will.
Use the scalloped side of the barrel nut wrench, not the side with pins. The scallops will engage more teeth and spread the stress over a larger area, reducing the chance of smearing our breaking the teeth.
Use the scalloped side of the barrel nut wrench, not the side with pins. The scallops will engage more teeth and spread the stress over a larger area, reducing the chance of smearing our breaking the teeth.
I don't think he has a wrench like that.
medicman816
11-23-18, 17:51
The wrench has the scallops on one side and 3 pins on the other. I've been using the scalloped side. I hadn't really thought about the aluminum being heat treated and iI'm glad i asked. I know its off topic but I'm curious how it holds up to full auto fire (not this one, uppers in general) and stays under 250 degrees.
joedirt199
11-23-18, 18:11
If you have a breaker bar to put in the AR wrench that helps. I use nylon covers made to go in a vice I got off ebay. The bottom one has holes and cross pins for the upper/lower joining pin holes. Top is groved to go over the flat top rail. It can be clamped down pretty tight and helps with those stubornly tight barrel nuts.
medicman816
11-23-18, 18:26
Update: One hour of freezer time followed by heating with a torch, then using the scalloped wrench with a breaker bar has proven unsuccessful. I'll wait a little while longer and see if there are any other ideas before cutting the nut off. Sending it out is likely to cost more than the upper ill likely destroy. Is there a need for these to be this tight? I have to assume that these are tighter than 80ft-lbs. Would it be unreasonable to put the impact wrench on the end of the brownells rod? I'm mostly joking.
Update: One hour of freezer time followed by heating with a torch, then using the scalloped wrench with a breaker bar has proven unsuccessful. I'll wait a little while longer and see if there are any other ideas before cutting the nut off. Sending it out is likely to cost more than the upper ill likely destroy. Is there a need for these to be this tight? I have to assume that these are tighter than 80ft-lbs. Would it be unreasonable to put the impact wrench on the end of the brownells rod? I'm mostly joking.
I think your loosening torque is being lost in distorting the indexing pin notch around the indexing pin instead of actually loosening the barrel nut. If you had them, the clam shell vise blocks might make a big difference.
medicman816
11-23-18, 19:15
Is there a preferred brand of vice block? Best I could do at the moment is clamp the upper in the vice with wooden blocks between the takedown lugs and across the top rail.
People seem to like these ones. > https://www.btibrands.com/product/delta-series-ar-15-upper-vise-block-clamp/
I've been wanting to try these ones. > https://rguns.net/shop/r-guns-a3-receiver-vice-block/
medicman816
11-23-18, 19:58
Ordered... Now we wait...
Thanks for everything. Hopefully I'll be back in a few days with good news.
The clam shell vise blocks aren't super expensive, so it's certainly worth the try... It just might work out.
Update: I'll wait a little while longer and see if there are any other ideas before cutting the nut off.
No need to destroy the upper.
If you have a four or five inch vise and it is securely mounted either make or buy a set of barrel clamps.
Get some help to hold the armorers wrench securely onto the nut, use the breaker bar and slide a pipe over it to add extra leverage (a cheater bar - most of the time I use an old piece of chain link top rail) pull.
If that outruns the grip of your barrel clamps line them with some appropriate sized rubber hose and try again - you can generally buy 1/2 to 1 foot of appropriately sized hose at a hardware store.
Using the barrel clamps probably runs about the same risk of shearing the index pin as do the receiver blocks but applies less stress to the receiver.
If you cant get it loose and need to cut the barrel nut take a dremel and cut about half way through the nut. Try to loosen it, the nut may split or give enough to get it off. I'd start conservative and cut a bit more each time it doesn't work, less chance of getting to the threads. Try to orient so the end of the 'scalloped' area of the wrench are on the ejection port side of the groove in the nut, not bridging the groove.
You can also cut more than one groove.
26 Inf,
He isn't going to get anywhere new with barrel blocks, he's already been using the Brownells barrel extension tool which accomplishes the same thing.
26 Inf,
He isn't going to get anywhere new with barrel blocks, he's already been using the Brownells barrel extension tool which accomplishes the same thing.
You are absolutely correct, I forgot that as I read through the thread, wondering why no one had mention barrel blocks. :rolleyes:
I have the knock off Geissele Reaction Rod from BOTACH, it has flats and is designed to be gripped in the vise as you use the armorer's wrench to apply the torques. If the OP has been using the Brownell's tool to apply torque while trying to hold the barrel nut into a vise mounted armorers wrench I could see some problems.
I would mount the Brownells tool in the vise (probably need to build or get vise blocks) and give that a shot.
(I'd guess that Brownell's didn't put flats or their barrel extension tool and wrote the instructions as they did to avoid conflict with Geissele)
medicman816
11-24-18, 13:09
The Brownells version has a 1/2" square socket in the end opposite the lugs. Placing a 1/2" socket wrench in that and then securing the round portion of the tool in the vise jaws, with the socket wrench up against the lower portion of the vise makes for a rather rigid setup, and the there is no way for the tool to rotate. The barrel is vertical in this orientation, but it could rather easily be placed horizontally. You can also secure the barrel wrench in the vise and use the 1/2 socket with a breaker bar. I have tried both ways and seem to get a better "grip" on things with the upper/rod/socket setup in the vise.
(I'd guess that Brownell's didn't put flats or their barrel extension tool and wrote the instructions as they did to avoid conflict with Geissele)
Actually, I'm pretty sure the Brownells barrel extension tool predates the Geissele Reaction Rod by a little... I may be wrong about that though. ;)
I remember seeing it when it first came out and thinking to myself, "that's a terrible idea" with the way the instructions read.
Actually, I'm pretty sure the Brownells barrel extension tool predates the Geissele Reaction Rod by a little... I may be wrong about that though. ;)
I remember seeing it when it first came out and thinking to myself, "that's a terrible idea" with the way the instructions read.
I don't know, either. They both show up in threads from 2012 on this site.
jackblack73
11-24-18, 18:02
With my first BCM, I actually broke the upper receiver trying to remove the barrel nut. Tried many of the suggestions in this thread, but as you know, that sucker is on tight. The second time I needed to remove a barrel nut from a BCM, I went straight to cutting it off.
With my first BCM, I actually broke the upper receiver trying to remove the barrel nut. Tried many of the suggestions in this thread, but as you know, that sucker is on tight. The second time I needed to remove a barrel nut from a BCM, I went straight to cutting it off.
I'm glad you can get blemished ones nowadays on the cheap. Did you end purchasing new upper?
jackblack73
11-25-18, 13:31
I'm glad you can get blemished ones nowadays on the cheap. Did you end purchasing new upper?
This was my first AR and a complete BCM rifle. So fortunately BCM let me buy a new upper receiver with the BCM marking at a slight discount, as long as I sent them the old one. So I sent them everything and had them remove the barrel nut and, of course, send back to me uninstalled.
I’d send it to BCM and ask them to remove it. If they won’t ask for a warranty repair and to have the barrel nut installed to spec which it clearly isn’t.
I’ve disassembled Colt factory uppers and the barrel but comes off with a crappy AR multi wrench and firm hand force. I’m no Superman either, technically I have a light build.
This makes me never want to buy a BCM upper with a factory barrel nut. Thanks for the heads up.
bamashooter
11-25-18, 21:44
Had one mil-spec barrel nut give fits. Eventually dremeled the delta assembly off due to I had no more hand strength left to press the wrench against the nut. Strongest spring I'd ever seen. Removing the hand guards confirmed it. I used penetrating fluids, frozen it, heated it (multiple times) to the point of melting the front of the receiver block (with indirect heat-gun heat), 9 lb sledge, 4-5 ft breaker bar, hours and hours. Gave up. Told a buddy about it the following morning and he said bring it over. Took my block and receiver, put them in his vise and said, "Hand me that "gun" wrench. Sticks the wrench on and one wack with a very nice, high dollar dead blow hammer broke the nut loose easily. Didn't even wind up, just a nice wack. From the time I handed the wrench to him, less than thirty seconds it was freed. Stunned, I shook my head and thanked him. Receiver and pin were just fine. Sometimes crap just happens. Sure seems to be the norm with the BCMs.
Had one mil-spec barrel nut give fits. Eventually dremeled the delta assembly off due to I had no more hand strength left to press the wrench against the nut. Strongest spring I'd ever seen. Removing the hand guards confirmed it. I used penetrating fluids, frozen it, heated it (multiple times) to the point of melting the front of the receiver block (with indirect heat-gun heat), 9 lb sledge, 4-5 ft breaker bar, hours and hours. Gave up. Told a buddy about it the following morning and he said bring it over. Took my block and receiver, put them in his vise and said, "Hand me that "gun" wrench. Sticks the wrench on and one wack with a very nice, high dollar dead blow hammer broke the nut loose easily. Didn't even wind up, just a nice wack. From the time I handed the wrench to him, less than thirty seconds it was freed. Stunned, I shook my head and thanked him. Receiver and pin were just fine. Sometimes crap just happens. Sure seems to be the norm with the BCMs.
Do you remember seeing any sign of grease on the disassembled receiver and barrel nut?
I also have a very nice, high dollar (Snap-On) dead blow hammer at my disposal, so I will keep that in mind.
goaltendah1
11-26-18, 04:21
I removed a BCM barrel nut the other day. I was using the Magpul Armorers Wrench. It was definitely on there, but I got it off with some serious weight behind it.
My barrel nut and receiver both had grease on the threads.
Jeff
I removed a BCM barrel nut the other day. I was using the Magpul Armorers Wrench. It was definitely on there, but I got it off with some serious weight behind it.
My barrel nut and receiver both had grease on the threads.
Jeff
White lithium or Moly?
Robb Jensen
11-26-18, 10:09
PROTIP: When removing bbl nuts ALWAYS use the clam shell type upper block which also has the inner upper support piece. I use the Brownells one. If you're worried about it leaving rub marks on your upper use masking/painters tape on the upper where the block contact it. I'd also suggest using the multiple pinned side of the Magpul wrench.
I put a piece of pipe on the end of my wrench to give me more leverage...gives me better feel I thought. I also use the clam shell.
bamashooter
11-26-18, 12:27
Do you remember seeing any sign of grease on the disassembled receiver and barrel nut?
I also have a very nice, high dollar (Snap-On) dead blow hammer at my disposal, so I will keep that in mind.
Though I observed a fine white line where the barrel nut attaches to the rcvr, it was a thick grease-like substance. However, like one other I did, it was not on the threads of the nut or receiver. Almost like a perfect bead of soft caulk. I mean perfect. Perhaps a tiny concave toward the receiver. I was under the impression that the threads had been lubed and the "bead" I observed was "squished-out" grease. Evidently not the case. I remember because I ran a toothpick around the circumference about a 1/2" or so and a tiny bit stuck (very thin smear) to the toothpick. Bottom line, neither 2 had any visible substance on the barrel nut or receiver thread. Dry as a bone. I have the nut and cut-up pieces of delta assembly stored in a baggie. Just pulled them out, examined, ran finger, all of that kind of stuff and there's zero substance on them. One of the nuts was a PSA assembly and the one where the dead-blow was used was DPMS.
Though I observed a fine white line where the barrel nut attaches to the rcvr, it was a thick grease-like substance. However, like one other I did, it was not on the threads of the nut or receiver. Almost like a perfect bead of soft caulk. I mean perfect. Perhaps a tiny concave toward the receiver. I was under the impression that the threads had been lubed and the "bead" I observed was "squished-out" grease. Evidently not the case. I remember because I ran a toothpick around the circumference about a 1/2" or so and a tiny bit stuck (very thin smear) to the toothpick. Bottom line, neither 2 had any visible substance on the barrel nut or receiver thread. Dry as a bone. I have the nut and cut-up pieces of delta assembly stored in a baggie. Just pulled them out, examined, ran finger, all of that kind of stuff and there's zero substance on them. One of the nuts was a PSA assembly and the one where the dead-blow was used was DPMS.
Thanks for checking... Proper assembly with moly grease seems to be hit or miss outside of Colt.
goaltendah1
11-26-18, 15:41
White lithium or Moly?
I honestly don't know. It was silver/gray in appearance.
Jeff
I honestly don't know. It was silver/gray in appearance.
Jeff
Doesn't sound like white lithium grease, maybe they've changed to something different.
I honestly don't know. It was silver/gray in appearance.
Jeff
More than likely it was Aeroshell 33MS
I wonder if the OP removed the barrel nut? :confused:
medicman816
12-02-18, 23:05
Still waiting on the clam shell vise block to arrive. Guess they were overwhelmed with Black Friday orders. Hoping by the weekend but no rush at the moment. Was hoping to get it off when I originally posted as I had a shooting trip planned. Will be a week or two till I can go again.
medicman816
12-13-18, 18:05
And... SUCCESS!!!
Big thanks to everyone who. All of this knowledge is certainly going in my toolbox for later use.
21 days after the original post (read about it below if you're so inclined)
I totally recommend the clam shell style vise block listed above. The nut was off within a minute and with what seemed like much less effort than the reaction rod, not to mention less than 1/2 of the price.
Boy was this an interesting ride. The first clamshell was ordered along with a few other items on a black friday sale. I missed the email from the retailer saying "sorry, we no longer carry it but were shipping the rest of your order anyways." The order arrived and, surprise, no vise block. I then ordered through the retailer listed above, got a confirmation page afterwards, but no e-mail, until 3 days later saying "you have this in your cart, did you still want it." So "ordered it" a second time and it finally arrived today.
Good deal, thanks for letting us know.
Great! I'm happy that it worked out.
Does your indexing pin look okay? Also, how does the indexing pin notch on the upper receiver look? Specifically on the left and right sides where the pin makes contact with the notch. You might see an impression of the pin from the aluminum crushing around it.
You might have to clean the notch up pretty good (I use brake cleaner) to see any damage.
If there happens to be no damage it will be a double win. ;)
bamashooter
12-14-18, 08:11
Glad to see you prevailed. OP, are you saying that due to the clam shell you had success removing the nut as compared to your attempt using a rod?
titsonritz
12-14-18, 11:59
Glad to see you prevailed. OP, are you saying that due to the clam shell you had success removing the nut as compared to your attempt using a rod?
I wouldn't doubt it based on this IG tidbit alone...
https://www.m4carbine.net/showthread.php?177352-Wrench-and-vise-block&p=2226401#post2226401
...one of many good threads on the subject of tools.
medicman816
12-14-18, 13:13
Index pin and slot appear undamaged when I cleaned the old grease off. I was thinking, and correctly it seems, that it would be ok considering that there was zero noticeable movement on the wrench with the rod.
I am 99% saying that the clamshell was the trick. Using the reaction style rod, penetrating oil, and differential cooling was unsuccessful after 2ish hours of trying. The clamshell took less than a minute without differential cooling or additional oil (although there was residual oil from the first attempt on the nut for the past 3 weeks. I guess in fairness I should have tried the rod again to see if 3 weeks of oil helped any). There was also significantly less effort applied. The previous attempt was moving the workbench the vise is mounted to, this attempt did not.
I wish I had been able to find that thread before this saga began. It was not among those listed in my search results prior to starting this, I searched for advice on which tool to start with and it seemed 50/50 rod/clamshell.
No damage, double win. :smile:
And you had to clean off the old grease, so dry assembly wasn't the problem.
medicman816
12-14-18, 14:54
There was definitely grease on the threads. It was whiter than other barrel grease that I have seen, but my sample size is small here. Seemed almost like pipe dope.
The more I think about it I think it was just on really tight. It seemed like a tire lug nut that is put on with an air impact wrench. A regular lug wrench won't budge it, but a cheater bar makes it seem rather easy. Had it been seized, the oil and heat should have worked, or the clamshell wouldn't have either.
bamashooter
12-14-18, 18:10
Thanks medicman816.
Good info. I’ve been trying to decide on what type of vise block.
Sent from my iPhone using Tapatalk
Index pin and slot appear undamaged when I cleaned the old grease off. I was thinking, and correctly it seems, that it would be ok considering that there was zero noticeable movement on the wrench with the rod.
I am 99% saying that the clamshell was the trick. Using the reaction style rod, penetrating oil, and differential cooling was unsuccessful after 2ish hours of trying. The clamshell took less than a minute without differential cooling or additional oil (although there was residual oil from the first attempt on the nut for the past 3 weeks. I guess in fairness I should have tried the rod again to see if 3 weeks of oil helped any). There was also significantly less effort applied. The previous attempt was moving the workbench the vise is mounted to, this attempt did not.
I wish I had been able to find that thread before this saga began. It was not among those listed in my search results prior to starting this, I searched for advice on which tool to start with and it seemed 50/50 rod/clamshell.
Can you provide a link to which clamshell show you purchased?
There was definitely grease on the threads. It was whiter than other barrel grease that I have seen, but my sample size is small here. Seemed almost like pipe dope.
The more I think about it I think it was just on really tight. It seemed like a tire lug nut that is put on with an air impact wrench. A regular lug wrench won't budge it, but a cheater bar makes it seem rather easy. Had it been seized, the oil and heat should have worked, or the clamshell wouldn't have either.
Looks like BCM doesn't use good stuff on the threads to prevent galling/seizing and ease future nut removal. Anyone know exactly what they use? Is it just plain white lithium grease?
Was the white stuff oily or dried out? EDIT: nevermind, you soaked it in oil for 3 weeks lol.
FWIW, Colt uses Molykote G-N Metal Assembly Paste. Probably to prevent this very thing from happening.
medicman816
01-05-19, 12:27
People seem to like these ones. > https://www.btibrands.com/product/delta-series-ar-15-upper-vise-block-clamp/
Was this one, from these guys.
[QUOTE=Artiz;2692658]Looks like BCM doesn't use proper stuff on the threads to prevent galling/seizing and ease future nut removal. Anyone know exactly what they use? Is it just plain white lithium grease?
FWIW, Colt uses Molykote G-N Metal Assembly Paste.
Can't comment on this as I have no idea if the stuff they used meets the "spec." There was no galling/seizing. Removal was easy once I got the proper tool. Was probably on the upper range of the torque spec. As stated above, it seems logical that the "reaction rod" was trying to shear the alignment pin rather than turning the nut. My sample size it too small to be all scientific about it though.
As stated above, it seems logical that the "reaction rod" was trying to shear the alignment pin rather than turning the nut. My sample size it too small to be all scientific about it though.
Yes, reaction rods transfer the torque into the index pin and upper slot, while upper blocks and the like transfer the torque through the threads/upper as it should be, that's where the torque in the nut exerts force to keep it in place, in the threads.
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