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

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Ben86

Ben86

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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.
 
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.
 
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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.
 
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
 
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.
 
Not sure why he is trying to do anything with the flash hider in the first place.
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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.
 
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.
Click to expand...

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

ChileRelleno said:
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.
Click to expand...

So what part of Dixie are you located? ;) I'm in Perkinston, MS.
 
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.
 
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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.
 
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.
 
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.
 
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..
 
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?
 
Are you running a barrel with a pinned flash hider?
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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. ;)
 
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.
 
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.
Click to expand...

what lug? on the f.s.?
 
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.
 
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.
 
what lug? on the f.s.?
Click to expand...

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.
Click to expand...

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