View Full Version : BCG gets stuck real bad...
I've fired 46 rounds consecutively with no issues with this custom upper. However, rounds 47, 48, 49, and 50 all run into the same issue. The rounds I used were Federal American Eagle Brass Rounds.
One thing I do have to note is that between rounds 46-47. I took the upper to a gun smith who polished the area up a bit and it was freely able to cycle. I tested it out at home my manually cycling though 30 rounds and it operated smoothly. HOWEVER, after firing shot #47, the problem returned and it seems to have reached a point that it will continue to happen unless something is done.
It basically gets stuck so hard that I HAD to slam the buttstock while pulling on the charging handle just so I can eject the round. The malfunction was exactly the same in all 4 of those cases. Also, getting into battery was near impossible after round 50. Even with the help of the forward assist it would not go.
I made a video illustrating the issue I had and I was wondering if anyone could ID what the cause might be.
http://www.youtube.com/watch?v=8B3eGEOmgus&feature=youtu.be
Heavy Metal
10-25-13, 12:00
You are either getting gas tube interference from a crooked tube, your cam pin can't clear the slot or something is fubar inside your BCG.
bluejackets92fs
10-25-13, 12:40
Might be helpful if you list the spec of the rifle.
Can you clarify a couple of things?
1. Does this upper ONLY have 50 rounds on it or were you having troubles THEN you had your run of 46 shots before the issue resurfaced?
2. What exactly did the gunsmith polish?
3. Did you build this & what brand are the components? Just curious.
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We need a little more info. The make and model. What upper spec, etc...
Off hand sounds like BCG, or chamber issues. Get us more info there are a lot of knowledgeable guys here.
It bears reiterating. Please give us more info so we don't play 20 questions.
It could be anything.
I'd suggest you have someone who knows what they're doing with ARs take a look at it.
It doesn't sound like the "gunsmith" meets that criteria.
Heavy Metal
10-25-13, 14:42
For starters, strip the bolt from the bolt carrier and see if it(the carrier) binds by itself.
The first step in troubleshooting is to eliminate the potential sources for the problem.
Nothing on an AR15 requires polishing to work correctly. I hope you didn't pay this so called gunsmith anything.
Since the OP has been back and not commented I have to wonder about this post? Hopefully he will be along soon to update us.
Since the OP has been back and not commented I have to wonder about this post? Hopefully he will be along soon to update us.
Was curious if he logged in since or not. I always wonder why people abandon their posts. :confused:
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A photo of the bolt carrier group removed from the rifle would help.
Things I have seen while training people with very little knowledge about firearms that could cause this are:
1) The bolt was inserted in the bolt carrier backwards when assembled.
2) The firing pin retaining pin was inserted in the wrong side of the bolt carrier.
3) The gas rings were galled after someone dicked them up with a cleaning brush making the bolt bind inside the bolt carrier.
As others have said, more information would be helpful.
The only way that can happen is if the bolt is defective. In which. case there are bigger issues at hand.
I suspect the OP was either doing something wrong or its a non-issue since has been back and doesn't want to update us.
A photo of the bolt carrier group removed from the rifle would help.
Things I have seen while training people with very little knowledge about firearms that could cause this are:
1) The bolt was inserted in the bolt carrier backwards when assembled.
2) The firing pin retaining pin was inserted in the wrong side of the bolt carrier.
3) The gas rings were galled after someone dicked them up with a cleaning brush making the bolt bind inside the bolt carrier.
As others have said, more information would be helpful.
Can you clarify a couple of things?
1. Does this upper ONLY have 50 rounds on it or were you having troubles THEN you had your run of 46 shots before the issue resurfaced?
2. What exactly did the gunsmith polish?
3. Did you build this & what brand are the components? Just curious.
Sent via Tapatalk
I've been out on vacation since the day I posted this and I haven't had a chance to log into a cpu/laptop until today. The content is as follows:
1) The lifetime round count is 50 rounds, with every round since the 47th having the same malfunction
2) The gunsmith polished the area where bolt makes contact with the barrel, don't know what its called exactly (think its the chamber... but see further notes below as to why I think this is no longer the area of concern)
3)The guys at Weapon Outfitters put this together.
The components is as follows
- Parallax Tactical Upper Receiver
- Centurion Arms 14.5 inch Barrel
- Centurion Arms CMR handguard
- Centurion Arms LowPro Gas Block
- BCM Gunfighter Ambi Charging Handle
- Fail Zero BCG
*** All Purchased Brand New
-----------------------
Additional Info (Discovered 10/27/2013)
- I removed the Bolt and slid ONLY the carrier by itself down until I reached a stopping point. Interestingly enough, it still stops at the same location. My buddies BCM BCG does exactly the same thing without a bolt.
Doesn't seem like the bolt is a problem, given that the BCG doesn't go into battery without a Bolt. (same stopping point)
- I've contacted Weapon Outfitters and haven't gotten a response since the day I posted this. Prior to getting it shipped to my house a month back when it was purchased there along with the pin and welding services, something went wrong but I was told the issue was purely an aesthetic problem and that it would be good to go. It seems that the problem is no longer just a minor dink when they pinned my gas block. It seems the issue is one of a canted gas tube and my rigg is all pinned and welded flash hider and gas block :(
So the problem arised after the polishing was done? Correct?
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So the problem arised after the polishing was done? Correct?
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Well, we polished it as a response to the original problem and it seem to have fixed up momentarily. (though it returned immediately one round after that, as the problem was something else it seems)
I went back to them and decided to try sliding Bolt Carriers without the bolt to see if it was a canted gas block issue and it seemed to be the case.
Weapon Outfitters never quite got back to me in the past few days either. I'm hoping my emails dont get dodged or something.
Can you take pics of the carrier & the interior of your upper?
Also, just curious, did he polish the lugs on the bolt or on the barrel extension?
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Quote:
Originally Posted by T2C
1) The bolt was inserted in the bolt carrier backwards when assembled.[
The only way that can happen is if the bolt is defective. In which. case there are bigger issues at hand.
I suspect the OP was either doing something wrong or its a non-issue since has been back and doesn't want to update us.
We don't know what the "gunsmith" did to the carbine.
I have seen bolts reversed during assembly on contract carbines on two occasions. The bolt cam pin would slip into the bolt from both sides. Both rifles worked after I rotated the bolt 180 degrees. I inspected several other rifles that would do the same thing, so I had to add instructional material to cover this issue during training.
Low bid carbines operated by people with little interest in firearms. :angry:
did he polish the lugs on the bolt or on the barrel extension?
The barrel extension.
Here's a new video testing the carrier WITHOUT a bolt
http://www.youtube.com/watch?v=ivuGvGKF0xY&feature=youtu.be
(http://postimg.org/image/4bqmywefn/full/)
online photo storage (http://postimage.org/)
[img]http://s16.postimg.org/slylez6p1/20131027_154843.jpg (http://postimg.org/image/r6x0q95lt/full/)
how to screenshot on windows (http://postimage.org/app.php)
It was barrel extension that got polished (this isnt the same gunsmith that constructed the upper BTW it was the guys at weapon outfitters)
I'm not sure what happened to the post I wrote up not too long ago and why it needed approval but in short, here's a NEW video along with images
I'm REALLY wishing right now that this was some error I caused out of stupidity as those would of been fixable with a few adjustments. I've played no part in the actual construction of the rifle (I only picked out the parts) and unfortunately, I can't just take this rifle apart and fix the issue myself without the tools or the skill sets. I received his upper with the assurance from support that it would be in "capable fighting condition"
----Video Link--------
http://www.youtube.com/watch?v=ivuGvGKF0xY&feature=youtu.be
-------------------------------
http://s13.postimg.org/3yz8spw5z/20131027_154851.jpg
http://s16.postimg.org/slylez6p1/20131027_154843.jpg
Is there something lodged in the bolt carrier key? A cotton swab perhaps? A spent primer?
Is there something lodged in the bolt carrier key? A cotton swab perhaps? A spent primer?
I went and checked out just now with a flash light and just to be sure im not missing anything, I used a toothpick to see if there was anything that could possibly a result of a clog.
Unfortunately there was nothing in there. I would of loved to have had this whole thing fixed by doing just that but I really feel like the issue comes from a canted gas tube.
Something is out of spec. The key looks alright but it does look like there's rubbing in the upper. I wonder if the charging handle is binding between the gas key & the upper. Hard to tell on my phone & I'm taking the kids Trick or Treating right now so I won't be at a PC for awhile to take closer look.
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TacticalMark
10-27-13, 16:44
Is the gas tube perfectly straight? looks slightly shifted to the left or its the angle of the picture. Gently try the carrier without the CH and see where it stops.
I went ahead and took off the charging handle and did a test with the bolt on AND off.
The results are the same unfortunately. (The carrier by itself ends in the same stopping place :( ) I don't have any gunsmith locally that can do or undo pin and welding and Weapon Outfitters has yet to get back with me.
I've never had an issue with Fail Zero before and I find it strange if it were the source of issue. However I don't consider that to be outside the realm of possibility. I am however leaning more towards the canted gas tube route considering everything I have done to diagnose the problem.
TacticalMark
10-27-13, 16:54
Do you have another carrier you could try for troubleshooting? Do you have calipers for taking some measurements?
If the end of the gas tube is distorted or off center it could cause this issue.
Let us know what Weapon Outfitters has to do to get the rifle running.
Do you have another carrier you could try for troubleshooting? Do you have calipers for taking some measurements?
In the shop, we tried BCM to see if the results were the same but at that time, we didn't test it the way I was testing it today with the bolt removed since we originally suspected that the issue was with the bolt making contact with the barrel extension.
I don't have any tools for further testing and right now and I'm really wanting to get rid of this rifle for $ since it doesn't work. Of course, how can I sell something that wont even function? This has left me quite frustrated.
If by some chance I get in touch with weapon outfitters, I'll keep everyone updated. I've already had a few emails sent out but Its been days and I have not got a response.
If you have a small mirror, you can view the bolt carrier key and gas tube. Shine a light on the mirror to illuminate the area and see if the end of the gas tube lines up with the bolt carrier key.
Before you insert the bolt carrier, view the end of the forward assist and make certain it is not sticking far enough inside the receiver to bind on the bolt carrier.
Put some red ink or paint on the end of the gas tube, then insert the carrier to see if the tube is aligning with the key.
If you have a small mirror, you can view the bolt carrier key and gas tube. Shine a light on the mirror to illuminate the area and see if the end of the gas tube lines up with the bolt carrier key.
Before you insert the bolt carrier, view the end of the forward assist and make certain it is not sticking far enough inside the receiver to bind on the bolt carrier.
I wanted to try that but then I already had my upper packed and ready the moment I got an email from them. (phew! I thought Id never get a response since my last email took weeks for one)
At this point, I'll just have to hear from them what the problem is and report it when I get a full diagnosis.
Thanks you all for your patience and effort. I will take what I have learned here and apply it to future issues that I run into.
Let us know what Weapon Outfitters has to do to get the rifle running.
Let me provide a brief recap. I would suggest you do this methodically or else you are simply pissing in the ocean to raise the water level.
Place the upper receiver flat on a table so you are looking down onto the inside of the gas tube. See if the gas tube is centered left and right.
Take the bolt carrier without the bolt and slowly insert it into the upper. I suggest that everything be cleaned or at least wiped down.
If the carrier is binding on the tube, you should be able to feel it. If it is then you need to tweak it and recheck it. I would also look and see if the gas tube was installed incorrectly.
If none of this works then I suggest you remove the gas tube and then recheck the BCG and see if the key is defective. If there is no binding without the tube I would guess that is the case.
If it passes then the issue is the tube.
First and foremost I would contact Weapon Outfitters and tell them you want to send the entire upper back for them to examine and you need to clearly explain what is happening. You should not be troubleshooting a new upper.
I had this very problem once. It turned out that it was the gas tube was slightly bent out of the box. A new gas tube resolved the issue.
i agree with others that the gas tube looks tweaked. i would try the old trick of taking a red permanent marker and markering the end of the gas tube up to see how it is seating. also if you can get in there with a dial caliper you might be able to see if it is twisted to one side or the other.
i agree with others that the gas tube looks tweaked. i would try the old trick of taking a red permanent marker and markering the end of the gas tube up to see how it is seating. also if you can get in there with a dial caliper you might be able to see if it is twisted to one side or the other.
I think that might have been mentioned in post #29:rolleyes:
Mall_Ninja
10-31-13, 22:35
Seems like lots of people posting without reading first...not just regular users...
I reached out to Weapon Outfitters about the issue and was told they are taking care of it. He thinks he knows the issue based upon some previous information. Hopefully we will get some feedback soon from the OP.
In general, i don't trust any gun that hasn't been test fired. I had mentioned this to Gambit when he first got in touch with me, but we had another upper where another customer requested we do a build but they would supply the FailZero bolt carrier group. In that upper, the rifle would bind hard, and get jammed at about the same location Gambit's gun binds in the videos. After some diagnosis, we figured out the FailZero gas key was binding on the gas tube. Swapped the FZ gas key for a Stag Arms gas key and fixed all issues. I sent the FZ gas key back with the fixed upper to the customer: wish I had it now for reference though.
Just got Gambit's upper back, and first thing I did was test fire with a LMT bolt carrier group: no problem. I'm gonna experiment with the Fail Zero BCG tomorrow but it's nice to know that it's not the gas tube. The FZ BCG seems to move freely and smoothly as well though.
Unfortunately, forgot to ask Gambit to include the charging handle. I am thinking that is one component that could be important in solving this mystery. I am currently using a Rainier Arms Raptor for testing, will try a Mod A44 VLTOR/BCM and see if that causes any issues. Hopefully the problem manifests itself tomorrow so I can better diagnose the issue.
All in all, only thing I can say with certainty is that I personally do not trust FailZero bolt carrier groups.
Not that it's of much use, but when I first read the title of this thread I thought of Ni Bor. I own a BCG as well that uses this treatment. From reading on this very site there are things that should be done to ensure proper function when utilizing this process and tolerance stacking issues can be exasperated if those processes aren't followed.
All in all, only thing I can say with certainty is that I personally do not trust FailZero bolt carrier groups. Me either. I bought a couple Fail Zeroes when they were all I could fine. Both had been buffed so extensively that half the tube portion thickness on the gas key was ground away.
http://i82.photobucket.com/albums/j248/87228/gastube_zpsf090b24d.png (http://s82.photobucket.com/user/87228/media/gastube_zpsf090b24d.png.html)
Those marks don't look normal. It is hard to tell, but it looks like crap stuck on to the gas tube, maybe some FailZero coating transferring onto the gas tube?
Got the upper back and did some testing. It seems to me that the malfunction might have been related to the Gas Key on the FZ BCG's dimensions being slightly altered by Nickel Boron coating. However, over the course of testing, the part must have worn in enough that they no longer are causing an issue.
For the record, if there is every any issue with an upper I build i'll rebuilt it, free of charge. I prefer to do complete builds with BCGs of known consistency (BCM, LMT, Centurion, Rainier Arms etc), gauge, and test fire just to be on the safe side.
Ammunition used for testing was Remington UMC 223
1. Fired one full magazine with LMT BCG, no issues
2. Fired 20 rounds with FZ BCG, one major malfunction.
a. Bolt seized 90% closed with live round in chamber, required mortaring.
b. Racked the rifle when the BCG was freed, and this time the BCG was able to fully seat, but the BCG was jammed shut. Mortared it to eject and extract the live round.
c. BCG jammed on a empty chamber, which required mortaring to free it.
3. Cleaned and lubed.
4. Fired 120 rounds with FZ BCG, no malfunctions.
5. Did 2 photoshoots with the rifle
6. Fired a full 30 round magazine with FZ BCG, no malfunctions.
Based on what occurred and my inability to replicate the malfunction more than once, I'm convinced the interior of the gas key was just slightly too tight at first, and through lubrication and firing is no longer an issue.
As a side note to curious readers: never use Q-tips on your gas key: the cotton fibers can act as a congealer with lube and carbon and block gas: i wouldn't believe it to be an issue if I hadn't seen it before. Also use a worn bore brush to clean the gas key.
Further thoughts on the "Fail Zero" BCG:
When playing around with it, I noticed that when i put the bolt into the locked position, dry, it basically jammed itself in place, require a light tapping with a rubber mallet to unjam. I lubricated generously with Fireclean and it no longer would get stuck. For a coating that supposedly reduces friction, it sure does seem to generate a lot of friction without lubricant present. I suspect the coating adds a few thousandths to the dimensions, and as such, required a "break in".
All in all, I still prefer phosphate coated, MIL-SPEC or similiar BCGs from manufacturers who've spent years making em.
Thanks for the updates.
This is one reason why i'm not too big on NiB BCG's, when a milspec BCG from BCM, Colt, or LMT will suffice.
Glad you got it sorted.
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