PDA

View Full Version : Colt LE 6920 problem


Brush Okie
07-17-2016, 21:51
I picked up a LE6920 a couple of years ago. I have shot less than 1000 rounds through it all factory ammo nothing exotic.

Took it out today to zero the rifle. Went through about 40 rounds. I was using iron sights but accuracy sucked, I figured it was the new ammo I was trying out it did not like.

I took it apart for cleaning and as part of the process pulled apart the bolt carrier group as usual. When I went to put the bolt back into the carrier group it would not go in. The gas rings seem to have expanded and bolt no go. On the back of the bolt where it connects with the gas tube it has rings that are rough when you feel them. The gas tube is a bit loose in the upper as well.

Any ideas? Can I just get a new bolt or do I need a whole carrier group? Is there something else going on? Be happy to hear any advice etc.

I am going to call Colt tomorrow and see what they say, it should not break with the low round count, and has not been abused in any way.

35NCO
07-17-2016, 22:04
It is hard to understand from your description without handling it. Can you compress the gas rings with your fingers and still insert the bolt into the carrier?

If not, I would replace the rings. Strange as I have never heard of rings expanding like that. Unless something else got into your carrier and mangled them up. Pretty rare to happen.

Gas tube loose how? It can be a little loose in play up and down. But if you can slide it back and forth horizontal, then you need to check your sight/gas block and find out why. Maybe a missing or worn gas tube pin. Which will need replacing and possibly a new gas tube if the gas tube pin hole it out of round or spec.


Sounds stange for a colt. Pics would help.

Brush Okie
07-17-2016, 22:38
It is hard to understand from your description without handling it. Can you compress the gas rings with your fingers and still insert the bolt into the carrier?

If not, I would replace the rings. Strange as I have never heard of rings expanding like that. Unless something else got into your carrier and mangled them up. Pretty rare to happen.

Gas tube loose how? It can be a little loose in play up and down. But if you can slide it back and forth horizontal, then you need to check your sight/gas block and find out why. Maybe a missing or worn gas tube pin. Which will need replacing and possibly a new gas tube if the gas tube pin hole it out of round or spec.


Sounds stange for a colt. Pics would help.

Thanks

Yes the gas rings expanded and will not fit in. I can not compress them enough to get it all the way in. I thought it was weird as well. I put the bolt carrier group in a bag so will try to dig them out later for a photo.

The gas tube goes up and down, not back and forth. Like I said I have not aboused the weapon at all. I don't babby it but dont beat it either, just back and forth to the range and factory ammo.

Brush Okie
07-17-2016, 22:41
here is a cell phone photo

Combat Diver
07-18-2016, 03:48
First inspect the gas key on the bolt carrier of looses. Tighten and restake if needed.
Gas tube if secured properly within the Front Sight Base it can lift up slightly as it is only anchored on one end. As long as the end isn't hitting and flatting out on the gas key your GTG.
Gas rings, replace, they are cheap enough but agreed they should go longer. You should be able to compress that ring. I normally replace the bolts first here on the teams at the prescribed 6,000 rds maniantence schedule. When you reinstall the gas rings be sure that the openings are offset about 1/3 turn from each other. Don't have an answer about the carbon/wear rings on the tail of the bolt.
One other thing, hold the upper receiver in one hand and barrel in the other and twist. They should not move. If the move just a bit then you need to retorque your barrel nut down (55 ft lbs). A loose barrel will cause all your problems.




CD

BryanK
07-18-2016, 04:54
First inspect the gas key on the bolt carrier of looses. Tighten and restake if needed.

Also, ensure that the key is not bent downward, or the hole/tube is not compressed (pinched). They make a carrier key tool for this that ensures "roundness". The only way to ensure the key is not bent downward without a calibrated eyeball, is to do a "pair-test"(I don't know the proper nomenclature for this test, but it works). You can re-straighten the carrier key (if bent) with a flat head BFS prying upward (carefully).

The "Pair-Test" for lack of a better term, is when you take the stripped bolt carrier(bolt, firing pin, firing pin retaining pin, and bolt cam removed), and you insert it into the upper. Now, tilt the upper to roughly 45 degrees and attempt to slide the bolt carrier forward. It should slide into battery easily and smoothly, and fall back under it's own weight. Do this a couple of times to see if there is any binding. If so, it's either a bent gas tube (I'll explain how this can happen further down in my replies) or a bent/out-of-round carrier key

Gas tube if secured properly within the Front Sight Base it can lift up slightly as it is only anchored on one end. As long as the end isn't hitting and flatting out on the gas key your GTG.

Nothing to add.

Gas rings, replace, they are cheap enough but agreed they should go longer. You should be able to compress that ring. I normally replace the bolts first here on the teams at the prescribed 6,000 rds maniantence schedule. When you reinstall the gas rings be sure that the openings are offset about 1/3 turn from each other.

Nothing to add.

Don't have an answer about the carbon/wear rings on the tail of the bolt.

Me either. That's really odd. The only thing I can think of is gas is making it past the rings and leaving a "skid mark" of sorts.

One other thing, hold the upper receiver in one hand and barrel in the other and twist. They should not move. If the move just a bit then you need to retorque your barrel nut down (55 ft lbs). A loose barrel will cause all your problems.

Not only a loose barrel, but a misaligned barrel nut will cause this too. If the previous owner/factory did not align the nut properly, it will bind up the gas tube. It will force the tube left or right and cause these issues. The pair-test will help diagnose how out of whack it is after your process of elimination starts.



CD

To piggy-back on CD for a moment...

Brush Okie, my additions are in blue. I've been out of the game for a while doing direct support on these critters, but if memory serves, you should at least be able to figure out where the problem is.

If you don't have the tools or time, take it to your local 'smith who is well versed in evil black rifles.

Brush Okie
07-20-2016, 23:54
First inspect the gas key on the bolt carrier of looses. Tighten and restake if needed.
Gas tube if secured properly within the Front Sight Base it can lift up slightly as it is only anchored on one end. As long as the end isn't hitting and flatting out on the gas key your GTG.
Gas rings, replace, they are cheap enough but agreed they should go longer. You should be able to compress that ring. I normally replace the bolts first here on the teams at the prescribed 6,000 rds maniantence schedule. When you reinstall the gas rings be sure that the openings are offset about 1/3 turn from each other. Don't have an answer about the carbon/wear rings on the tail of the bolt.
One other thing, hold the upper receiver in one hand and barrel in the other and twist. They should not move. If the move just a bit then you need to retorque your barrel nut down (55 ft lbs). A loose barrel will cause all your problems.




CD

+ Bryank

Thanks for the info. I looked at it and replaced the gas rings. For some reason the factory gas rings were very tight in there ie they would not spin on the bolt very easy and bolt had a lot of friction when turning it in the bolt carrier. Also the bolt when moving it in and out was hard to move and hung up.

I replaced the gas rings and the ones I bought slapped right in. They spin with ease yet when inserting bolt into bolt carrier they go in with what feels like the correct amount of drag. Also the bolt moves in and out of the carrier with the right drag but does not bind up like before.

My GUESS is the original gas rings were out of spec from factory.

The fact it shot without jamming does impress me. I remember going through OUST at Ft Benning mid 80's using the old A1. Some of the were jam o maticks and others ran fine.

If any of you folks make it to Ft Lewis area I will buy you a beer. I live in the small town 1st group jumps at a lot.

The Reaper
07-21-2016, 07:08
Colt's quality control has gone to hell.

They appear to be pushing junk out the door these days as fast as they can. :rolleyes:

TR

Streck-Fu
07-21-2016, 07:44
They did not seem to emerge from bankruptcy with a focus on quality products. Arguably, they have been crap since losing the gov contract.

Divemaster
07-22-2016, 06:58
Colt's quality control has gone to hell.

They appear to be pushing junk out the door these days as fast as they can. :rolleyes:

TR

Valuable comment. I've been trying to decide between a Colt and a BCM AR. Since Colt is not expensive and is a government supplier, I was leaning that way.

The Reaper
07-22-2016, 07:42
Valuable comment. I've been trying to decide between a Colt and a BCM AR. Since Colt is not expensive and is a government supplier, I was leaning that way.

There will be tremendously fewer problems with the Bravo Company rifle, and it will be to MILSPEC as well.

TR

35NCO
07-24-2016, 19:33
Glad to hear you got it running again.

If you get a chance, take a dial or digital caliper to those colt rings on face and side. Then compare those specs to your new ones.

I have never heard of the issue you seemed to have. Wondering if it's a spec problem or a metallurgical one. I have to guess they have some how thermally expanded. If they were out of spec, they may have honed up your carrier and caused a lot of premature wear. Sounds like your okay, but take a good look inside the carrier bolt channel.

If you tossed them already oh well...just was worth looking into more.

Patrin
07-25-2016, 17:22
Colt's quality control has gone to hell.

They appear to be pushing junk out the door these days as fast as they can. :rolleyes:

TR

That's disheartening to hear...I have 4 Colts, nothing that's recent mfg., but they are all quality. Dang...another American company shoveling shit...like Glock USA.:rolleyes:

Looks like it's BCM or LMT for my future acquisitions.

Brush Okie
07-25-2016, 18:25
Glad to hear you got it running again.

If you get a chance, take a dial or digital caliper to those colt rings on face and side. Then compare those specs to your new ones.

I have never heard of the issue you seemed to have. Wondering if it's a spec problem or a metallurgical one. I have to guess they have some how thermally expanded. If they were out of spec, they may have honed up your carrier and caused a lot of premature wear. Sounds like your okay, but take a good look inside the carrier bolt channel.

If you tossed them already oh well...just was worth looking into more.

I already tossed them but good idea wish I had miked them vs new ones. The good news is I have had zero jams with the rifle since I bought it. I am sure colt does not make gas rings probably a contracted. I will pull it apart next chance but the bolt seems nice and tight without binding like it should.

I did notice accuracy was carp but that might be the ammo. I will make some hand loads and get a box of good ammo before any decision is made. It might not like 55 gr8 ammo.

Patrin
07-25-2016, 18:38
I did notice accuracy was carp but that might be the ammo. I will make some hand loads and get a box of good ammo before any decision is made. It might not like 55 gr8 ammo.

That shouldn't be it...I run cheap Golden / Silver Bear ammo through my trainer Colt, a 6720 with pencil barrel, and get very satisfactory accuracy and, it's a mix of 55 and 62 grain. Hits to 600 yards on steel with A2 sights.

You should be able to run any ammo through that Colt barrel...some of the best made barrels historically...and not be below 'good enough for government work'.

frostfire
07-28-2016, 15:54
I already tossed them but good idea wish I had miked them vs new ones. The good news is I have had zero jams with the rifle since I bought it. I am sure colt does not make gas rings probably a contracted. I will pull it apart next chance but the bolt seems nice and tight without binding like it should.

I did notice accuracy was carp but that might be the ammo. I will make some hand loads and get a box of good ammo before any decision is made. It might not like 55 gr8 ammo.

https://www.youtube.com/watch?v=ua7xaWXMz0U
Seems you're better off with Radical Firearms. Surprisingly last well for non-gucci AR