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Mark One
04-14-2009, 5:41 PM
Well I have been loosing sleep over this little thing thinking that I am causing excess wear on my BCM Mid-length upper. So I have decided to come here and ask you guys what you think.

Here is a picture :
http://i149.photobucket.com/albums/s45/eclipse100000/100_0023-1.jpg

If you cant tell, the wear is the strip of metal that the charging handle has eroded away. At first I thought it was just the anodizing and did not pay much attention to it until I decided to run my finger nail across it. Now I can tell that it is not just the anodizing but also a little bit of the metal too.

I am using a CMT charging handle, the one that Bravo Company sells with the little raised part on the top.

So is this wear normal for a rifle with only a couple hundred rounds through it?

cmace22
04-14-2009, 7:11 PM
I would have to say no. I think during an average range shoot I use my carging handle maybe 2 times. How often do you use the carging handle. For it to wear like thank after only a few hundred rounds, I think you would have noticed a loud grinding sound every time you used it! Does it move freely with out the BCG in? If not I would look at replacing the CH.

Vtec44
04-14-2009, 7:15 PM
That's definitely not normal wear and tear at all. My stag has several hundred rounds to it and you can't even see the wear on the inside of the upper receiver.

Mark One
04-14-2009, 7:24 PM
Well... Sh*t

I have racked the charging handle quite a few times while messing with it. So its not just from a the range trips.

Should I contact BCM and tell them whats up? I purchased the charging handle from them when I purchased the upper so I figured all would be good.

technique
04-14-2009, 7:28 PM
can you post a pic of the area on the charging handle that is making contact with your upper?

Mark One
04-14-2009, 7:37 PM
Sure, I'll get the camera right now.

Edit: Pictures

http://i149.photobucket.com/albums/s45/eclipse100000/100_0024-1.jpg

http://i149.photobucket.com/albums/s45/eclipse100000/100_0025.jpg

Mark One
04-14-2009, 7:52 PM
Okay, there are some pictures of the charging handle

Omega13device
04-14-2009, 7:59 PM
Looks to me like the top of the gas key on the BCG is scraping the underside of the charging handle...how about some closeups of the gas key?

Vtec44
04-14-2009, 8:01 PM
Looks to me like the top of the gas key on the BCG is scraping the underside of the charging handle...how about some closeups of the gas key?

Good call. That's too small of a foot print for the charging handle.

technique
04-14-2009, 8:02 PM
Looks to me like the top of the gas key on the BCG is scraping the underside of the charging handle...how about some closeups of the gas key?

yeah looks like a tight fit, I would first say try a new CH. A standard one. I am surprised that the OP hasn't had any failures, or hasn't mentioned it anyway.

dchang0
04-14-2009, 8:07 PM
But the scrape is on the underside of the receiver's roof, not under the charging handle. It can't be the gas key. Looks to me like a sub-par anodizing/parkerizing job. In my own AR, the charging handle is worn to bare aluminum, but the receiver is not, and they have been together since brand new. Safe to say that the receiver's finish is tougher in my case.

In yours, you've got way too much wear in too short a time.

Pics of LMT's charging handle also show one of those weird raised nubs, as well as the PRI Gas Buster handle. BUT, your CMT's charging handle appears to have a much taller nub than the Gas Buster I own--by maybe 0.5mm.

cmace22
04-14-2009, 8:10 PM
Does your CH handle move freely with out drag with the BCG removed. If it does the problem is with the BCG/CH geometry. If it doesnt, then its the CH.

Mark One
04-14-2009, 8:11 PM
Here are some pictures of the gas key:

http://i149.photobucket.com/albums/s45/eclipse100000/100_0026.jpg

http://i149.photobucket.com/albums/s45/eclipse100000/100_0028-1.jpg

http://i149.photobucket.com/albums/s45/eclipse100000/100_0027.jpg

Its a BCM BCG

yeah looks like a tight fit, I would first say try a new CH. A standard one. I am surprised that the OP hasn't had any failures, or hasn't mentioned it anyway.

No, no failures so far...

Mark One
04-14-2009, 8:13 PM
Does your CH handle move freely with out drag with the BCG removed. If it does the problem is with the BCG/CH geometry. If it doesnt, then its the CH.

With the BCG out it moves freely but I can hear it scraping on something (guessing the top). But I do not need any force to move it back and forward.

cmace22
04-14-2009, 8:14 PM
yeah looks like a tight fit, I would first say try a new CH. A standard one. I am surprised that the OP hasn't had any failures, or hasn't mentioned it anyway.

Probably wouldnt, the charging handle is only used for manual cycling of the action the rest of the time its locked in the forward position. Unless the CH was interfering with the BCG for some reason.

cmace22
04-14-2009, 8:16 PM
With the BCG out it moves freely but I can hear it scraping on something (guessing the top). But I do not need any force to move it back and forward.


Incert your BCG in the upper, without pinning the upper/lower together move the CH back and forth. Is there noticable drap VS without the BCH.

ar15barrels
04-14-2009, 8:19 PM
With the BCG out it moves freely but I can hear it scraping on something (guessing the top). But I do not need any force to move it back and forward.

Of course it moves easy.
You wore through the tight spot already.

The charging handle is out of spec.
The receiver is toast.
Both should be replaced if you are worried about it.
If you are not worried about it, file off the high spot on the charging handle and add lube.

Mark One
04-14-2009, 8:20 PM
Incert your BCG in the upper, without pinning the upper/lower together move the CH back and forth. Is there noticable drap VS without the BCH.

Is by drap you mean more resistance than yes there is. But not by much and its hard to tell if it is just because of the weight of the BCG being pulled by the CH.

technique
04-14-2009, 8:22 PM
Probably wouldnt, the charging handle is only used for manual cycling of the action the rest of the time its locked in the forward position. Unless the CH was interfering with the BCG for some reason.

Well... Sh*t

I have racked the charging handle quite a few times while messing with it. So its not just from a the range trips.





I am using a CMT charging handle, the one that Bravo Company sells with the little raised part on the top.



IDK????

Mark One
04-14-2009, 8:22 PM
Of course it moves easy.
You wore through the tight spot already.

The charging handle is out of spec.
The receiver is toast.
Both should be replaced if you are worried about it.
If you are not worried about it, file off the high spot on the charging handle and add lube.

The receiver is toast?

Its not that I am worried about it, its that I paid a lot of money for quality parts and I expected quality parts. Bravo Company will be receiving a email shortly and I'll see what they say.

technique
04-14-2009, 8:23 PM
Of course it moves easy.
You wore through the tight spot already.

The charging handle is out of spec.
The receiver is toast.
Both should be replaced if you are worried about it.
If you are not worried about it, file off the high spot on the charging handle and add lube.

thats what I thought!!!!:thumbsup:

Mark One
04-14-2009, 8:29 PM
So do you guys think I should have Bravo Company replace the Upper and the CH? What about the BCG? Has that bee effected as well? (guessing not)

Well I am pretty pissed right now, I just hope that BCM does not give me any problems.

dchang0
04-14-2009, 8:32 PM
There is one possibility that the BCG pressed the charging handle up into the receiver as you were pulling on the charging handle, but that's not likely.

technique
04-14-2009, 8:34 PM
I wouldn't worry personally. If you can get them to replace the upper, more power to you. I would worry about the CH replacement first.

technique
04-14-2009, 8:36 PM
Wonder if the buffer area on the receiver is out of spec, maybe the buffer tube screws in at an angle. Usually you can tell and the wear would also be inside the buffer tube....I'm still going with bad CH.

ar15barrels
04-14-2009, 8:46 PM
Wonder if the buffer area on the receiver is out of spec, maybe the buffer tube screws in at an angle.

Would not matter.
The carrier is not mechanically joined to the buffer.

dchang0
04-14-2009, 8:48 PM
I think technique's imagining that the BCG may be hitting the inside of the buffer tube as the charging handle is being drawn back, thereby causing it to press the gas key into the charging handle and the charging handle into the roof of the receiver. But that should make a fairly obvious scraping noise, especially when the gun is being fired.

Mark One
04-14-2009, 9:12 PM
I think technique's imagining that the BCG may be hitting the inside of the buffer tube as the charging handle is being drawn back, thereby causing it to press the gas key into the charging handle and the charging handle into the roof of the receiver. But that should make a fairly obvious scraping noise, especially when the gun is being fired.

Wouldn't the bottom of the BCG be scrapped up if that were the case?

technique
04-14-2009, 9:19 PM
I think technique's imagining that the BCG may be hitting the inside of the buffer tube as the charging handle is being drawn back, thereby causing it to press the gas key into the charging handle and the charging handle into the roof of the receiver. But that should make a fairly obvious scraping noise, especially when the gun is being fired.

thats what I was imagining:thumbsup:

Mark One
04-14-2009, 9:43 PM
Is there a way to tell if the upper is in spec? Or the BCG? Or the CH?

I would like to find out what is causing the problem before I asked BCM to replace the parts.

technique
04-14-2009, 9:49 PM
I would go with what Randall said. Charging handle...

dchang0
04-14-2009, 9:56 PM
Is there a way to tell if the upper is in spec? Or the BCG? Or the CH?

I would like to find out what is causing the problem before I asked BCM to replace the parts.

Well, if you've got the measuring tools, such as digital calipers or a micrometer, you should be able to easily find the exact MILSPEC dimensions of the various parts in question and measure them. (Somebody posted a set of the diagrams here in some recent thread, and I believe that AR15.com has a set.)

Or, if you've got a buddy with an AR, you could try various parts from his/her gun. Alternately, you could bring it into a local, friendly shop and try new parts, but that would be bad karma if you don't buy anything. Local gunsmiths like Randall at AR15barrels might also be able to help you diagnose/measure the parts in person--be sure to tip them generously!

Mark One
04-14-2009, 10:36 PM
Thank you guys for all of the help.

I am going to try and get BCM to replace the upper and charging handle. If I see any new wear on the new upper I will know it is either the BCG or what technique was imagining could be a problem.

I'll let you guys know how it goes