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Posted: 8/22/2013 7:21:02 PM EDT
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I just got this Colt 6920 and so far have not been impressed. It jams. A lot. Sometimes nearly every round and then sometimes I can go through 20 or more rounds without it jamming. I dont think that it is pulling back far enough. It comes about halfway back and grabs in the middle of the casing and scores it before it jams in the neck of the barrel.
I have tried all different combinations of different ammo with 4 different magazines. I tried some reloaded brass and I had to manually chamber a round every time. (I also tried some magazines, E-Launder or something like that and those wont even push the rounds up high enough for the gun to catch the rounds). I bought the colt because I had heard that they are of good quality but I am second guessing the purchase now... |
Colt gas ports are spec for 5.56 ammo so if your using reloads or other under powered ammo this is your problem. This is just a possibility and guess since there is limited info on explanation but look at the simple problems first. I have seen Colt rifles with this type of problem but once good ammo was used and a couple hundred rounds were fired then the cheap ammo cycled fine. I hope this is your problem and no major gas issue.
Clean and lube properly Use quality ammo Use quality Magazines (Dont overload Mags download 2) |
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Quoted:
if you put 1 round in the magazine and fire it, does it lock back on the empty mag? This will be your first step. Colts almost always are G2G, however, every company from time to time will spit out a random one that has a QC issue. Test this out, and if it doesn't lock back then you have a gas system issue. If this ends up being the problem, I'm sure Colt will take care of you. ETA: This will also be dependent on magazines. If you are using shitty ones, then it's possible it is not an issue with the rifle. |
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I just got this Colt 6920 and so far have not been impressed. It jams. A lot. Sometimes nearly every round and then sometimes I can go through 20 or more rounds without it jamming. I dont think that it is pulling back far enough. It comes about halfway back and grabs in the middle of the casing and scores it before it jams in the neck of the barrel. I have tried all different combinations of different ammo with 4 different magazines. I tried some reloaded brass and I had to manually chamber a round every time. (I also tried some magazines, E-Launder or something like that and those wont even push the rounds up high enough for the gun to catch the rounds). I bought the colt because I had heard that they are of good quality but I am second guessing the purchase now... First, as Gamma suggested, clean the chamber thoroughly, then completely disassemble the bolt carrier group (BCG), clean it and lube it correctly and retest. You stated you tried different brands of ammo and mags. These are most likely not the cause. First check the allowable travel for the BCG by pulling back on the charging handle, pressing the bolt release until the catch is in the locking position and slowly return the carrier by riding the charging handle forward until it is held by the bolt catch. You should have approximately 3/16" of travel. If you have significantly less, then this might alter the reciprocating speed of the carrier due to a shorter distance of travel. If the previous troubleshooting checks out, then place only one round at a time into a magazine and fire for effect. Repeat this test several times, using multiple magazines if possible. The bolt should lock back after each round fired in this manner, with the face of the bolt being held by the bolt catch and not the carrier itself. If this test fails to lock at all, then you are most likely experiencing short stroking. If the carrier itself is held by the catch, and not the bolt, then I would suspect that your carrier is cycling too fast. But, this is not a definitive symptom that the rate is too high, since it will usually still fully cycle without catching at all. Post your results and we can troubleshoot from there. |
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I have tried all different combinations of different ammo with 4 different magazines. I tried some reloaded brass and I had to manually chamber a round every time. Can you be more specific to which brands of ammo you said you used, pics would be great. Perform a good cleaning; however I would say it sounds like a ammo problem. Is the weapon brand new out of the box or did you buy it from someone? |
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I would start with simple first
What are you using for lubing ?? I think You need to clean everything and relube with Quality Lube. I have had great Success with Synthetic motor oil Mobil 1 5w 30 has worked great for me and is cheap I know other guys use other synthetics I have used Mobil 1 and stuck with it cause it works. |
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More information needed.
You just got this Colt 6920... Did you buy it brand new from a gun store? Used guns no matter how unused they look can often hide problems. A previous owner might have sold it because he screwed it up in some way, and can't figure out how to fix it. Has it been altered in some way by a previous owner, OR the gun store, OR you? Even though there are lots of part for sale that can be installed by anybody, there are a million and one ways to screw up an installation/modification. Did you buy maintenance supplies to go with your new toy? A cleaning kit and proper lubricating oil is what I'm asking about. Did you clean the gun inside with gun cleaner and brush before you started shooting it. Storage fluids left inside the gun could gunk up and cause operating problems. Are you aware that new guns need a break in period (at least 500 full power rounds Lake City/Federal M193 55gr or M855 62 gr is what I'm talking about) for all the parts to start to mate and for the gun to start operating reliably? |
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What Gamma said. EVERY manufacturer ships rifles with preservative coatings, not lubricants. And just about every manufacturer's user manual says "first, clean and lubricate the rifle." Lubrication is important with a new rifle because all the moving parts are fresh and typically (particularly with Colt) "less than smooth." This helps the parts retain lubricant, but it also requires plenty of lube while the parts break in. Most ARs work a lot better after 500-700 rounds because those moving parts have "broken in" and now slide much better among themselves. And the bolt and carrier are THE most critical places where we see this sort of need for break in.
Use quality, full-power ammunition for the first several hundred rounds, expect the trigger to start out kind of yucky, and don't sweat "OMG, only 3" groups at 100 yards!!!!" until everything is running smoothly. You'll feel a difference in the effort to pull the charging handle, and the way it feels too, as the parts break in. When that "silky" feeling shows up, then you can start judging how the trigger feels, whether you're getting the groups you want, etc. |
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And in answer to the original question, yes it could be a gas tube issue. (Bent, cracked, loose). Look for gassing signs...
Yes it needs cleaned/lubed out of the box and yes it might be your ammo. If someone changed out hand guards or/and messed with the FSB or gas block, the gas port might not be lined up. |
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Quoted:
Can you be more specific to which brands of ammo you said you used, pics would be great. Perform a good cleaning; however I would say it sounds like a ammo problem. Is the weapon brand new out of the box or did you buy it from someone? Quoted:
Quoted:
I have tried all different combinations of different ammo with 4 different magazines. I tried some reloaded brass and I had to manually chamber a round every time. Can you be more specific to which brands of ammo you said you used, pics would be great. Perform a good cleaning; however I would say it sounds like a ammo problem. Is the weapon brand new out of the box or did you buy it from someone? I would also like to know what ammo. People say they use many different types of ammo, that doesn't mean it wasn't all the same grade of crap or low spec ammo. |
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http://www.xs400.com/forum/picture.php?albumid=623&pictureid=4439
http://www.xs400.com/forum/picture.php?albumid=623&pictureid=4440 http://www.xs400.com/forum/picture.php?albumid=623&pictureid=4438 Yes I have cleaned it. Several times. I have taken the bolt carrier group clear apart and scrubbed each piece with CLP and re-greased with gun grease. Like I said, I bought it from a guy. There were a few different mags with it. There were 4 E-Launder Mags, 1 mag that says "Law Enforcement Only" on it and a small ten round mag that has no name on it at all. I later bought a P Mag. The ammo I have tried first was Wolf, then Tulammo and some reloaded brass. The reloads were not as hot as the others and did not perform near as well. The hand grips are Magpul, which I guess would be after market. The casings are getting ejected. But the bolt is catching the casings somewhere in the middle and scoring them. I can not tell if it is when it is ejecting the brass or trying to pick it up. I need to be able to shoot reloaded brass, and I thought that this Colt would not have a problem but I seem to be wrong So, how do you tell if the gas port is not lined up and you are getting blow by? |
| Try some decent brass 5.56 and see how that goes. The ammo you used could very well be the problem. Any time you use steel case ammo and have problems you should clean the rifle and shoot some known decent ammo to make sure you actually have a problem at all. Some guns just dont like steel or under powered ammo. |
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Your problem is the ammo. You should be able to shoot brass reloads just fine, but you will have to experiment with the loads in order to find a good combination that will run the rifle correctly. And you may have to do that continuously as you change primer, powder, bullet, and brass lots.
Just because someone put some reloads together does not mean they will automatically run just any rifle. Even if they followed a formula to the T. |
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Wolf and Tula are among the weakest loaded ammo around, and some factory rifles have problems with them. Tula especially has a different pressure curve which seems to not perform well with carbine gas rifle configurations like your Colt.
If the reloads are noticeably weaker than those two, it seems likely that you're just getting short stroking - insufficient energy is going into the operating system to correctly cycle the action. And I'd tend to avoid those reloads. Try some ammo loaded to a more reasonable pressure and see if that doesn't solve your problems. |
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Quoted:
Wolf and Tula are among the weakest loaded ammo around, and some factory rifles have problems with them. Tula especially has a different pressure curve which seems to not perform well with carbine gas rifle configurations like your Colt. If the reloads are noticeably weaker than those two, it seems likely that you're just getting short stroking - insufficient energy is going into the operating system to correctly cycle the action. And I'd tend to avoid those reloads. Try some ammo loaded to a more reasonable pressure and see if that doesn't solve your problems. I fully concur with this advice. While the OP "may" have other issues (extra heavy buffer, etc.), low powered ammo is a Bad Thing. Especially Tula. And as you say, if the reloads "didn't seem as hot as the others" then they are really lame. OP, buy some factory-made 5.56mm-class ammunition (plunk down some cash and get some XM855 - it's worth it) and you will almost certainly see a whole lot of difference. Then examine the rest of the rifle for whether your setup is customized for heavy loads or has some odd issue; you gas tube almost certainly is doing its job, it just doesn't seem that you've given it enough to work with (by using low powered ammo). |
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Quoted: I just got this Colt 6920 and so far have not been impressed. It jams. A lot. Sometimes nearly every round and then sometimes I can go through 20 or more rounds without it jamming. I dont think that it is pulling back far enough. It comes about halfway back and grabs in the middle of the casing and scores it before it jams in the neck of the barrel. I have tried all different combinations of different ammo with 4 different magazines. I tried some reloaded brass and I had to manually chamber a round every time. (I also tried some magazines, E-Launder or something like that and those wont even push the rounds up high enough for the gun to catch the rounds). I bought the colt because I had heard that they are of good quality but I am second guessing the purchase now... Some people consider their reloads good ammo, which most of it is not. I would hold off on second guessing until you know what the problem is. From your words it sounds like you are very unfamiliar with the platform and probably need to know how to use it correctly. Quoted: re-greased with gun grease. . The ammo I have tried first was Wolf, then Tulammo and some reloaded brass. The reloads were not as hot as the others and did not perform near as well. since you bought it second hand, tell us what buffer it has. You are not dealing with a new colt, you are dealing with a rifle somebody probably modded with a heavy buffer and heavy spring from the advice of the idiots on this board. |
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