View Full Version : Colt 6920 help
Hey guys I could use a little guidance. I have a Colt 6920 that I've been trying to get JP VTAC free float hand guard installed on. So far I've gone to 2 different gun smiths and I've been told the barrel nut is on too tight and they can't get it off regardless of what they've tired. So finally I've decided I'm just going to get the tools and try it myself before shipping it off to JP (which I'd really rather not do as I need this thing ASAP for work). Anyone have any suggestions? Everyone here so far seems to be much more knowledgeable than me when it comes to things such as this any any help would be greatly appreciated. Also I'm fairly new to the forums so if this isn't the place for this thread I apologize.
Soak it overnight with Kroil. With a decent size vice, secure it in an upper receiver action block. Use an armorers wrench that engages all of the teeth (not the GI type), then lean into it. If that does not work, let it sit in the freezer for a few hours, then try again.
Kroil or PB blaster. I recommend the PRI barrel nut wrench and DPMS panther claw vice block.
Soak it overnight with Kroil. With a decent size vice, secure it in an upper receiver action block. Use an armorers wrench that engages all of the teeth (not the GI type), then lean into it. If that does not work, let it sit in the freezer for a few hours, then try again.
I'll 2nd that. Stick it in the freezer overnight.
I had the same issue with my new 6920 earlier this year. My gunsmith said that he had never seen one that tight (and he has worked on thousands of these). We ended up applying some heat, and using a pipe on the end of the barrel wrench for more leverage. We eventually got it lose, but broke several of the teeth in the process. I'd never heard of the freezer thing, otherwise perhaps I would have given that a try.
Cut off the delta ring, spring and snap ring with a pair of bolt cutters or dremel. Then use a pipe wrench on barrel nut.
Heavy Metal
12-23-10, 22:34
Kroil plus freezer overnight will do it.
I got it done but the receiver cracked in the process and the post on the barrel bent. Not a good situation, so I ended up just spending the money on a new complete upper from Colt and using what I could salvage from the old upper to build a junk gun to be used as a range toy.
Can you explain this a little further? I really don't understand how this can happen if you followed the steps.
I have done literally hundreds of barrels and I am really confused? :confused:
I got it done but the receiver cracked in the process and the post on the barrel bent. Not a good situation, so I ended up just spending the money on a new complete upper from Colt and using what I could salvage from the old upper to build a junk gun to be used as a range toy.
No way the receiver cracked if it was fixtured properly. Shearing the index pin is a 1 in 10 occurrence with new Colt barrels but can be easily repaired. Pictures are worth a thousand words...
Sure thing. I picked up the pri barrel nut wrench and vice block from Brownells. I soaked in Kroil over the course of a few days. The day of the removal I froze the upper in the freezer for 8 hours. Took off the flash hider and fsb with ease. Clamped everything down in the vice made sure it was secure attached the wrench and with a little elbow grease I. Got the nut to come right off. Upon compleation I was getting ready to apply the loc tite to the threaded portion of the upper where the barrel attaches and it was then that I noticed there was a piece of the threaded collar broken off right at the notch that the barrel slides into. Then when I inspected the barrel the stem that slid into said notch in the receiver was bent. So it almost looked like that part of the barrel sheared the threaded chunk off the receiver. The barrel nut came off really easily for me so I'm kinda wondering if this is something that happened when I brought this thing to one of the two gunsmiths I originally had attempt this and they just covered it up. Who knows. I feel like I did my homework though and did my part. Any ideas?
Ill post some pics when I get a chance.
Sure thing. I picked up the pri barrel nut wrench and vice block from Brownells. I soaked in Kroil over the course of a few days. The day of the removal I froze the upper in the freezer for 8 hours. Took off the flash hider and fsb with ease. Clamped everything down in the vice made sure it was secure attached the wrench and with a little elbow grease I. Got the nut to come right off. Upon compleation I was getting ready to apply the loc tite to the threaded portion of the upper where the barrel attaches and it was then that I noticed there was a piece of the threaded collar broken off right at the notch that the barrel slides into. Then when I inspected the barrel the stem that slid into said notch in the receiver was bent. So it almost looked like that part of the barrel sheared the threaded chunk off the receiver. The barrel nut came off really easily for me so I'm kinda wondering if this is something that happened when I brought this thing to one of the two gunsmiths I originally had attempt this and they just covered it up. Who knows. I feel like I did my homework though and did my part. Any ideas?
Did one of the 'smiths use a barrel clamping block, instead of a proper receiver block, by chance? Also, DON'T PUT LOCTITE ON BARREL NUTS!!!!!!! :eek:
That sounds exactly like what happened. This is why I have said time and time again when you take an AR to some local butcher make sure that he has knowledge of the platform and aks questions.
Also, as a side note. Why were you going to put Loctite on the threads? This is completely unnecessary and creates more problems. Apply some anti-seize, torque or tighten it properly, install the gas tube and the rest of the stuff and that's it.
Sure thing. I picked up the pri barrel nut wrench and vice block from Brownells. I soaked in Kroil over the course of a few days. The day of the removal I froze the upper in the freezer for 8 hours. Took off the flash hider and fsb with ease. Clamped everything down in the vice made sure it was secure attached the wrench and with a little elbow grease I. Got the nut to come right off. Upon compleation I was getting ready to apply the loc tite to the threaded portion of the upper where the barrel attaches and it was then that I noticed there was a piece of the threaded collar broken off right at the notch that the barrel slides into. Then when I inspected the barrel the stem that slid into said notch in the receiver was bent. So it almost looked like that part of the barrel sheared the threaded chunk off the receiver. The barrel nut came off really easily for me so I'm kinda wondering if this is something that happened when I brought this thing to one of the two gunsmiths I originally had attempt this and they just covered it up. Who knows. I feel like I did my homework though and did my part. Any ideas?
The only reason I was going to use the loc tight was because it was in the instructions that JP sent with the handguard. As far as the gunsmiths go out here near Chicago its hard to find anyone that does this stuff so who knows if the guy was a hack. I'm reluctant to out right blame the guy because ill never really know. All I do know is this is my duty weapon and its cost me a lot of cash at this point. Is this bent index pin something I can remove or replace to salvage the barrel?
Did JP state to use Loctite on the barrel nut itself, or on the screws? I am not familar wth their particular set up.
It can be fixed (I'll let MK18 chime in) but I have never had to do it. At least you will be able to get a BCM M4 upper to replace the damaged one for less than the cost of a Colt.
The only reason I was going to use the loc tight was because it was in the instructions that JP sent with the handguard. As far as the gunsmiths go out here near Chicago its hard to find anyone that does this stuff so who knows if the guy was a hack. I'm reluctant to out right blame the guy because ill never really know. All I do know is this is my duty weapon and its cost me a lot of cash at this point. Is this bent index pin something I can remove or replace to salvage the barrel?
Yeah the JP instructions say to add a thin coat of red loc tite to the threaded portion of the barrel collar. I managed get a new stripped Colt upper cheap I'm just hoping I can still use the barrel for a range toy. Meanwhile for my duty weapon I just got a complete Colt LE6940 upper so I'm good there.
Does the JP set up require that you use a proprietary barrel nut? I have no idea why anyone would recommend that. Hopefully you can get it all resolved.
Yeah the JP instructions say to add a thin coat of red loc tite to the threaded portion of the barrel collar. I managed get a new stripped Colt upper cheap I'm just hoping I can still use the barrel for a range toy. Meanwhile for my duty weapon I just got a complete Colt LE6940 upper so I'm good there.
JP is probably recommending that you put the loctite in between the free float tube, and the OUTSIDE of the barrel nut, not between the nut, and upper receiver. Didn't think of that until he said the instructions recommended it.
They do have a proprietary barrel nut and I'll copy/paste the instructions here so you guys can see I'm not crazy :cool:
Installation procedure:
1. Lock the receiver in an action block or other suitable means. Be careful not to crush it.
2. Degrease the threaded area of the barrel collar and the interior threads of the larger aluminum
receiver nut. Some manufacturers use a Teflon coating on the receiver. Wr recommend that you
remove the coating from the threads with a stainless brushso that the Loc-Tit can bond.
3. Using the red 271 Loc-Tite, coat the threads of the receiver barrel collar and install the receiver
extension nut, turning it down until it stops. Then, back it off until the gas tube holes are in alignment.
Let that set for several hours hour until the Loc-Tit cures. It is important that the extension nut is solid
with the receiver or it will rotate when you tension the barrel collar against the flange of the barrel.
4. After the thread locker is set, slip the barrel extension piece into the receiver barrel collar. Make sure the extension piece pin is securely in the 12” locator notch in the receiver barrel collar. Apply a coating of anti-seize
compound onto the threads of the barrel retainer nut. Failing to do so may
cause the threads to gall and lock the two nuts together, ruining the aluminum
receiver extension nut. Slide the steel barrel lock nut over the barrel,
and turn it by hand until it stops against the extension piece flange. Then, using a standard armorers
wrench, apply 50 to 80 foot-pounds of torque as necessary to align the lock nut to the gas tube
channel.
5. Now, slide the tube over the barrel and onto the receiver extension nut. Index to the screw holes,
and install the seven 6x32 flat head screws to retain the tube.
6. Next, install the gas block/gas tube assembly and secure to the barrel by whatever method is necessary.
Finally, install the brake or flash suppressor if needed.
This seems alot like the way that YHM free floating rails are installed. In any case, I never put that crap on.
They do have a proprietary barrel nut and I'll copy/paste the instructions here so you guys can see I'm not crazy :cool:
Installation procedure:
1. Lock the receiver in an action block or other suitable means. Be careful not to crush it.
2. Degrease the threaded area of the barrel collar and the interior threads of the larger aluminum
receiver nut. Some manufacturers use a Teflon coating on the receiver. Wr recommend that you
remove the coating from the threads with a stainless brushso that the Loc-Tit can bond.
3. Using the red 271 Loc-Tite, coat the threads of the receiver barrel collar and install the receiver
extension nut, turning it down until it stops. Then, back it off until the gas tube holes are in alignment.
Let that set for several hours hour until the Loc-Tit cures. It is important that the extension nut is solid
with the receiver or it will rotate when you tension the barrel collar against the flange of the barrel.
4. After the thread locker is set, slip the barrel extension piece into the receiver barrel collar. Make sure the extension piece pin is securely in the 12” locator notch in the receiver barrel collar. Apply a coating of anti-seize
compound onto the threads of the barrel retainer nut. Failing to do so may
cause the threads to gall and lock the two nuts together, ruining the aluminum
receiver extension nut. Slide the steel barrel lock nut over the barrel,
and turn it by hand until it stops against the extension piece flange. Then, using a standard armorers
wrench, apply 50 to 80 foot-pounds of torque as necessary to align the lock nut to the gas tube
channel.
5. Now, slide the tube over the barrel and onto the receiver extension nut. Index to the screw holes,
and install the seven 6x32 flat head screws to retain the tube.
6. Next, install the gas block/gas tube assembly and secure to the barrel by whatever method is necessary.
Finally, install the brake or flash suppressor if needed.
The only reason I was going to use the loc tight was because it was in the instructions that JP sent with the handguard. As far as the gunsmiths go out here near Chicago its hard to find anyone that does this stuff so who knows if the guy was a hack. I'm reluctant to out right blame the guy because ill never really know. All I do know is this is my duty weapon and its cost me a lot of cash at this point. Is this bent index pin something I can remove or replace to salvage the barrel?
The index pin can be repaired but not by you. It will have to go to a machine shop who also has 1/8 replacement pins.
That's good news as that's something my father in law has access to. Thanks for all the input guys.
Since you're in the Chicago area, the only local gunsmith I would trust is Rich Dettelhouser at Canyon Creek Custom. He's in Streator.
That is good to know sir. Thank you kindly for that info. Its tough to find people that offer those services in this unfortuneate gun hating state.
After reading some of these threads on this forum, I thought all Colts were infallible? I'm devastated.
What is that supposed to mean?
After reading some of these threads on this forum, I thought all Colts were infallible? I'm devastated.
What is that supposed to mean?
Relax, sarcasm.
I am relaxed. Your snide sarcasm isn't welcome. So please start to make some posts of substance or find the door.
Relax, sarcasm.
Wolf Spyder
02-13-11, 04:10
nhp1127, I thought your sarcasm was funny. It made me smile.
The JP instructions do include the application of locktite. It's important to remember that the JP FF tube is pretty old tech now in the AR world, and as such things like indexing pins and tabs and collars weren't common at the time.
That said, since it is older tech, I'd suggest a more updated rail system. If you go with something like the Apex (http://www.apexcncmachine.com/) you don't have to remove the barrel nut and you still get that same rail-free tub profile where you can add rail sections where needed. If you go with something like the Daniel Defense Omega, or the Centurion Arms drop-in systems you'll get a full four rail system that attaches to the stock nut. In the case of the DD you won't have to remove anything more than the plastic handguards. Finally, the next gen of the Troy Extreme tubes, which have a single rail along the top, are going to be mounting to the stock nut. FWIW, Viking Tactics moved away from the JP to their own version of the Troy. One might consider this a clue.
I suspect that what happened to your upper was that one of the hacks you took the gun to jammed your upper in a vice and used the front sight base to try and turn the barrel when he couldn't figure out how to make the parts work correctly. IG has it spot on that if you can't find a 'smith that someone else can vouch for you need to either:
Send it to a known out of town armorer
Do it yourself
Use alternate products like I listed above that require no, or less, armorering.
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