Woe is me, for my A1 receiver cannot be removed.


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Ben86
August 15, 2011, 11:38 PM
I have a Bushmaster XM15 A1 carbine that I desperately wish to put optics on. Trying to adapt the carry handle is a joke, unless you've got the neck of a giraffe. It's more like a chin weld than a cheek weld.

I bought a Yankee Hill flat top upper receiver to put on it. Today I brought it to a local gunsmith (whom I consider the best around) and he could not get my gun apart to put the new receiver on. He almost striped the lug on the flashhider trying to get it off and could not even get the delta ring and all that other stuff at the base of the barrel to budge. He told me he has this problem a lot with Bushmasters for some reason. He thinks they fail to put any kind of lubricant between the metals which results in galling. He recommended that I contact Bushmaster and see if they can help me using their special equipment.

I'd like to know if anyone else here has any ideas or explanations. If only I would have got a flat top receiver in the first place! If this doesn't work out I'll probably just have to buy a complete upper assembly.

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roklok
August 15, 2011, 11:47 PM
Lug on the flashider ? Not sure why he is trying to do anything with the flash hider in the first place. It should not have to be touched to switch upper receivers. Also seems suspicious that he cant get the delta ring to budge. After the handguards are removed, a snap ring holds it in place, should be easy to remove. The barrel nut is the only thing that might possibly cause problems if galled.

Ben86
August 15, 2011, 11:51 PM
That's what I was wondering. He said he needed to take that off to get the front sight off, etc., etc. I'm kind of a noob at this but I thought all that could stay put and the barrel and all would just be popped off and put on the new receiver.

FlyinBryan
August 15, 2011, 11:55 PM
ya, he would really need to get the flash hider off to remove the barrel.

maybe he meant he nearly boogered up the flats on the flash hider?

EDIT: unless he could just knock out the taper pins, and slide the fsb to the flash hider, then remove the gas tube, then the barrel nut while the fsb is still on the barrel, but i dont know. ive never done it that way. i have always just took off the flash hider and slid the fsb off the end of the barrel with the gas tube still on the fsb

roklok
August 16, 2011, 12:00 AM
I have switched, installed quite a few barrels and uppers and have never touched the FSB or the flashhider. The gas tube is pulled to the rear after drifting pin out, no need to remove FSB, at least on a standard configuration AR. Maybe with some free float tubes. I cant imagine trying to drift the taper pins out of the FSB, when the little roll pin for the gas tube is so easy to remove. Then the gas tube is pulled to the rear and removed.

wally
August 16, 2011, 12:01 AM
Not sure why he is trying to do anything with the flash hider in the first place.

Is there some other way to remove the gas tube without removing the front sight base? The flash hider usually has to come off unless the barrel is long enough to let the gas tube clear the barrel nut when you slide the FSB (or gas block) forward. Otherwise you have to remove the gas tube from the gas block. To me its easier to remove the flash hider and just slip off the FSB and keep the gas tube FSB intact.

Are you sure its not one of those "permanently attached" flash hiders to make the barrel legal length? Otherwise try a propane torch on it first in case someone use Loc-Tite on it.

FlyinBryan
August 16, 2011, 12:10 AM
I cant imagine trying to drift the taper pins out of the FSB, when the little roll pin for the gas tube is so easy to remove.

hmm. i think most ppl remove the front sight base when removing the barrel.

roklok
August 16, 2011, 12:10 AM
Drift the gas tube pin out, pull gas tube rearward a half inch or so, pull sideways on gas tube, pull the gas tube out of the upper receiver past the FSB, no need to remove the FSB. I have done this on 14.5" through 20 " ARs with never a problem. The gas tube has enough spring in it to get past the FSB without deforming.

ChileRelleno
August 16, 2011, 12:28 AM
If he is installing some FF rails or some such, some have a proprietary barrel nut, e.g. DD Omega X.
Which necessitates removing the old barrel nut and hence the FH, FSB & Delta ring.

Muzzle devices can gall, not likely, but they can.
If red loctite was used he definitely needs to heat it up.
Also, if loctite was used, there would be no galling since it becomes a boundary layer between the metals.

Sounds to me like he needs another 'Competent' gunsmith.
I have all the necessary tools, vise blocks, bench/vise and etc... Bring it over, no cost.

Ben86
August 16, 2011, 12:42 AM
Now that I've done my research I really don't understand why he was trying to take the front sight and flash highder off. Roklok's described procedure seems to be a common way of doing it. Maybe he really didn't know what he was doing.

I'm just about determined to do it myself. I do most of my car work myself. To get the barrel off I just need the proper barrel wrench? How hard is it supposed to be tightened?

Sounds to me like he needs another 'Competent' gunsmith.
I have all the necessary tools, vise blocks, bench/vise and etc... Bring it over, no cost.

So what part of Dixie are you located? ;) I'm in Perkinston, MS.

ChileRelleno
August 16, 2011, 12:50 AM
Your just south of Wiggins, I'm in Mobile, not far at all.
I'm home some weekends, on the road the rest of the time, I'm a trucker.
Not sure which weekend I'll have off next.

Either a standard barrel nut wrench or proprietary, depending on Make, not sure about Bushy.
A torque wrench, anti-seize, a bench vise and much preferably, vise blocks to properly support the receiver(s)/barrel.
Torqueing a barrel nut is a 4 stage process, 35-40lbs tightened three times, then 40-80lbs as needed to align gas tube holes in nut/receiver.

AR-15 Rep
August 16, 2011, 01:23 AM
Not sure why he tried to remove the flash hider and front sight base, but depending on the handguard, removing the handguard, and gas tube is all one really needs to do to change the upper receiver. Of course some proper tools are required but should be a pretty simple project.

MrCleanOK
August 16, 2011, 04:47 AM
Yeah, you need a new smith. This guy doesn't know what he's doing. He may even be right about the barrel nut being galled up, but you have given us enough info already to demonstrate that this smith still doesn't know what he's doing with AR's.

CGRifleman
August 16, 2011, 06:01 AM
Apparently it is just a Bushmaster thing. I replaced my full Bushhmaster upper with a Vltor VIS but kept the barrel. The gunsmith who did it told me he'd never had a barrel nut put up that much of a fight.

Jeremy2171
August 16, 2011, 09:55 AM
Correct....if you are only swapping uppers and keeping the barrel/handguards the same...the only thing that needs to be removed is the gas tube and then the barrel nut. Switch uppers then install barrel and then gas tube.....the handguards etc..

TonyAngel
August 16, 2011, 07:01 PM
I wouldn't call the smith a nut just yet. I've seen a few funky things come from Bushmaster and Rock River.

I've had to use a pipe wrench to get the barrel nut loose on a few Bushmasters.

Are you running a barrel with a pinned flash hider?

Ben86
August 16, 2011, 07:37 PM
Are you running a barrel with a pinned flash hider?

It's not pinned but I now believe it is fixed. As in welded most likely. That would explain him not being able to get it off and warping the lug a bit. :rolleyes: It does not explain him messing with it in the first place.

According to him he did try to loosen the barrel nut however to no avail and suggested I try to get Bushmaster to take it off and bring it back to him to work on. I'm not sure if I want to bring it back to HIM but I'll see if Bushy would be so kind as to remove it for me. Apparently Bushys are notoriously hard to get off. Is there any kind of substance that can be spayed and allowed to set to help with seizing? I wanted to ask if he tried spaying some DW40 or remoil on it, but thought better of it. ;)

451 Detonics
August 16, 2011, 07:42 PM
This would work fine and you get to keep the best possible iron sights...it is my favorite system...

http://i188.photobucket.com/albums/z271/reloader1959/rifles/coltscopemount.jpg

CYANIDEGENOCIDE
August 16, 2011, 08:35 PM
PB Blaster or Kroil are both pretty good for penetrating stuck threads. Really the delta ring and barrel nut are pretty cheap parts; you could have replacements for less than $20 combined. I wouldn't feel too bad using a dremel to cut them off, in fact that is exactly what I did with the delta ring on a DPMS upper I wanted to free float (it seemed easier than disassembling everything). If you decide to cut the barrel nut don't cut all the way through, just start it on both sides and use a cold chisel to split it.

FlyinBryan
August 16, 2011, 08:54 PM
It's not pinned but I now believe it is fixed. As in welded most likely. That would explain him not being able to get it off and warping the lug a bit.

what lug? on the f.s.?

Z-Michigan
August 16, 2011, 09:28 PM
Follow the method described by Roklok and try to meet up with ChileRelleno. Do yourself a favor and put some penetrating oil on the receiver threads / barrel nut junction at least 1-2 days ahead of time just in case there is some corrosion or other problem there.

I believe it is common to remove the FSB and FH to change barrels, but it's not necessary if you're going to reuse the existing barrel nut and delta ring assembly.

TonyAngel
August 16, 2011, 10:55 PM
I'm not trying to knock Bushmasters or anything, but I do believe that their quality control has been sketchy and I've always thought that the biggest problem with Bushmasters hasn't been the quality of the parts, but the guys putting them together.

As I mentioned, I've seen at least a few that took the use of a pipe wrench (and a cheater bar) to get them loose. I just figure that on some, they have to really over torque the nut to get everything to line up for the gas tube and when you combine this with a failure to use any sort of anti-seize compound, you could have a problem. I know that on the ones that I had trouble with, I ultimately had to pull the front sight and flash hider to replace the boogered up barrel nut once I got it loose.

kwelz
August 16, 2011, 11:02 PM
Knowing BM it is entirely possible they put Locktite on it.

Ben86
August 16, 2011, 11:20 PM
what lug? on the f.s.?

Please excuse my incorrect vernacular. I mean the...flat sides on the flash hider that one can use to take it off (unless its permanently attached of course).

I wouldn't feel too bad using a dremel to cut them off, in fact that is exactly what I did with the delta ring on a DPMS upper I wanted to free float (it seemed easier than disassembling everything). If you decide to cut the barrel nut don't cut all the way through, just start it on both sides and use a cold chisel to split it.

I don't think I have the testicular fortitude to do that. But, that is a good idea if worst comes to worst.

Z-Michigan
August 16, 2011, 11:34 PM
Keep in mind the cost factor if this becomes a real pain. You can get a decent barreled upper (no carrier group) for under $300 - for example the DSA ZM-4 is $275 plus shipping, with a nitride treated barrel. You could also get a barrel alone to install in your YHM upper, but while the barrels can be had for $150 or less, finding one with a pinned FSB is more difficult and will likely put you close to the price of the DSA or another barreled upper.

madcratebuilder
August 17, 2011, 10:21 AM
As I mentioned, I've seen at least a few that took the use of a pipe wrench (and a cheater bar) to get them loose. I just figure that on some, they have to really over torque the nut to get everything to line up for the gas tube and when you combine this with a failure to use any sort of anti-seize compound, you could have a problem.

Do not use anti-seize on the barrel nut, it causes corrosion. Use moly grease as specified in the 23&P. Do not use grease with graphite in it either. A pipe wrench to remove a barrel nut is OK if the nut is already fubar, but a serviceable barrel nut can be easily removed with a good quality barrel nut wrench. Like the ones PRI sells.

I believe it is common to remove the FSB and FH to change barrels, but it's not necessary if you're going to reuse the existing barrel nut and delta ring assembly.

Agreed, but this was a upper only change, no need to touch the FH or FSB. This should have been a under one hour job.


Please excuse my incorrect vernacular. I mean the...flat sides on the flash hider that one can use to take it off (unless its permanently attached of course).

If this so called 'gunsmith' rolled the flats on the FH it's probably pinned and welded. This may have damaged the barrel. A screw on FH should come off with light pressure from a wrench. The FH is not torqued on that tight, it should have a peel washer or crush washer behind it for clocking if it's requires clocking, ie birdcage or phantom style.

TonyAngel
August 17, 2011, 06:05 PM
A pipe wrench to remove a barrel nut is OK if the nut is already fubar, but a serviceable barrel nut can be easily removed with a good quality barrel nut wrench. Like the ones PRI sells.

Yeah, the choice of the term "anti-seize" was not the best. I keep a tube of moly grease on my bench for such uses.

As for my choice of tools, you use what you have to and to infer that I could have easily removed any particular nut simply by using a different type of wrench is really presumptuous.

dprice3844444
August 17, 2011, 06:43 PM
it's only sposed to be like 30lb of torque

dprice3844444
August 17, 2011, 06:46 PM
i think madcrate may mean anything with graphite in it beacause graphite corrodes aluminum

permatex anti seize

Product Features
Contains high percentage of micro-fine copper flakes in a semi-synthetic grease carrier
Fortified with high quality rust and corrosion inhibitors
Temperature range: -30F to 1800F
Provides good electrical conductivity
Suggested Applications; Spark plug threads installed in aluminum, exhaust manifold bolts, engine bolts, oxygen sensors, knock sensors, thermostat housing bolts, fuel filter fittings and battery cable connections

Ben86
August 17, 2011, 08:13 PM
I called Bushmaster today and they offered to not only take the barrel off, but put my new receiver on for an extra $40 or less depending on work time, as well as pay the shipping. I decided to take them up on the offer and let the "pros" handle it. Sounds like a good deal to me; best way to make sure the job gets done as well as very cost effective. It beats either buying a new upper assembly (complete, or semi-complete), having to find someone else who is experienced with stubborn Bushmasters, or trying to wing it myself even though I am just learning how all this works.

I'm wondering if they have a way of removing and replacing a "permanent" flashhider. It's not as pretty since that gunsmith got to it.

Thanks everyone for the info. I have learned a lot about my rifle from this.

FlyinBryan
August 17, 2011, 10:09 PM
bushmasters customer service is some of the best in the industry, although they get a bad rap by some of the chart thumpers around the internet.

i have kimbers, colts, remingtons, brownings, savages, rugers, springfields, h&r's, along with more than 1 bushmaster, and their customer service is second to none.

you get to talk to an actual living human on the first try.

Mot45acp
August 17, 2011, 10:57 PM
I hate to be the bearer of bad news....BUT.... I believe something may have been overlooked. I think YHM uppers have M4 ramps and Bushy barrels do not. Your pieces may not be compatible. Might wanna check this before you ship parts. If it were the other way round you would be good.

Open up and check your feedramps. If you look at the YHM upper it should have ramps machined into it. The Bushmaster will just have them on the barrel extension and not the receiver.

Eta: if I'm right this will create a lip where the barrel overhangs the feed lips creating a feeding issue.

Ben86
August 18, 2011, 01:20 AM
The YHM receiver I have has no feed ramps built into it. It's just a hollow upper with only a forward assist and ejection port cover attached to it. The only feed ramps I see are on the Bushy barrel. The YHM upper I got is this one: http://www.midwayusa.com/viewProduct/default.aspx?productNumber=989015

I did do a test to see if this YHM upper fit my BM lower. It fit just fine and is even close in color.

benzy2
August 18, 2011, 01:47 AM
That upper has M4 feed ramps (extended).

Just for reference,

http://img169.imageshack.us/img169/9819/feedramps2.jpg

Mot45acp
August 18, 2011, 01:49 AM
The upper you linked has the M4 ramps.

madcratebuilder
August 18, 2011, 08:56 AM
I hate to be the bearer of bad news....BUT.... I believe something may have been overlooked. I think YHM uppers have M4 ramps and Bushy barrels do not. Your pieces may not be compatible. Might wanna check this before you ship parts. If it were the other way round you would be good.

Most newer A1 and A2 uppers from BM have M4 ramps. I have a A1 with M4 ramps and two A2's here I'm working on that have them. The early stuff from the 90's probably do not have them.

Ben86
August 18, 2011, 12:18 PM
From the looks of mine I think I'm ok. Both the barrel and new receiver seem to have M4 extensions from what my noobie self can tell.

New receiver:

http://i1089.photobucket.com/albums/i341/Ben861/IMG_0210.jpg

Old receiver and barrel:

http://i1089.photobucket.com/albums/i341/Ben861/IMG_0208.jpg

Thanks for the pics benzy2!

Mot45acp
August 18, 2011, 12:27 PM
Both appear to have M4 feed ramps....you are GTG.

Ben86
August 18, 2011, 06:07 PM
Thanks for bringing that up though. The more I know the better.

Ben86
September 22, 2011, 12:56 PM
I finally got the gun back a couple days ago with my A3 receiver put on. They charged about $60 total, but did a good job.

http://i1089.photobucket.com/albums/i341/Ben861/IMG_0221.jpg

But, for some reason the spring on the ejection port cover is not set right. Meaning it is not twisted for tension, just slid on. I'm not sure why they would even take it off. It's not a big deal, I can fix that myself.

They also failed to send me back the old A1 receiver. I called them today to ask them about it. The CS rep told me that they will look into it and call them back Monday. If it turns out what I say is true they will give me a new A1 receiver. I really just want my old one back so I can sell it, but if that's what they want to do.

Do companies usually keep old parts when you send something in? I thought they would assume I would want it back. Oh well the A3 is on and I'm good to go. :D

Until I can decide on a better optic I have a centerpoint 1x25mm $50 walmart special on it. It seems like a good red dot for the money. I really like its compact size. It has red and green as well as four different recticles including single dot, three dot, a center dot with two horizontal and one vertical bar at the bottom and a circle/cross hair with a dot in the center. I went with the tapco riser.

karlb
September 22, 2011, 07:14 PM
That looks like a 14.5" barrel with a pinned Phantom flash hider. No wonder your "gunsmith" couldn't get it off with a wrench.

ChileRelleno
September 22, 2011, 08:41 PM
NVM

TonyAngel
September 23, 2011, 03:00 AM
Ben, did you ask them about the dust cover spring? I usually install that before I put the barrel on and I really don't know if it can be removed and/or installed without taking the barrel nut loose. I've never tried. I'm only mentioning it because it would really suck if you tried to do it yourself and then not be able to and then have them tell you that it's your problem because you messed with it.

dprice3844444
September 23, 2011, 03:08 AM
it can,just pop off the lil c clip

Ben86
September 23, 2011, 12:36 PM
Tony, I didn't bother to ask CS about it because I'm almost certain they wouldn't be able to give me answer because tracking down the person who monkey'd with it would probably not be easy. What am i going to get? An apology? I still had to put it back on myself so it doesn't really matter to me.

What I did was remove the c clamp and pull the rod out the back. I did put a generous amount of rem oil on the outside of the receiver before I did this to reduce friction. I used a set of needle nose pliers with a towel over the rod. Then I torqued the spring properly, re-inserted the rod and put back that EVIL little c clamp and I now have a properly functioning ejection port cover again. I've heard this method can bend the rod, but I haven't had that happen yet. This was the second time I did it.

For God sakes Eugene Stoner, why a teeny, tiny C Clamp?!! :D At one point that thing jumped away from me like a tiny flee. Luckily I found it on the ground after 5 min of searching and put it back in its place using tweezers and a small flat head screwdriver to push it on.

TonyAngel
September 23, 2011, 01:12 PM
Oh, Ok. Good deal. I just wasn't sure that there was enough room to remove the pin. No big deal then.

sansone
September 23, 2011, 01:56 PM
I think those c clips are most of the space junk ..
glad all is well, and now we know why the FH wouldn't come off

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