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11/4/2014 7:47:54 PM EDT
Recently picked up a new upper receiver that will not accept a bolt carrier..........any bolt carrier.

Tried 4 different makes of carriers and none fit.   Only  way to make one fit would be to hammer into place.  


How common is this situation ??

gd
11/4/2014 7:57:35 PM EDT
[#1]
Sorry for the noob question... but did you pull the bolt out before inserting it into the upper?
11/4/2014 8:05:11 PM EDT
[#2]
An upper that you can't put a bolt carrier into is RARE.  But your problem is not thoroughly described.  Did you extend the bolt (in it's "unlocked" position), so that the cam pin was lined up with the key - and the channel in the top of the upper?
11/4/2014 8:09:18 PM EDT
[#3]
Gas tube centered?
11/4/2014 8:53:51 PM EDT
[#4]
As above, confirm that the bolt was "unlocked" and that the gas tube is aligned.  Although the BCG would go in some distance before it stopped if it was the gas tube...

You said you tried multiple BCG's?  If they wont go in at all, it should be visible why not.
11/4/2014 9:20:41 PM EDT
[#5]
Quote History
Quoted:
Sorry for the noob question... but did you pull the bolt out before inserting it into the upper?
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i bet this, watched a guy cuss out his out of spec pos AR at the range when his new nitride bcg did not fit.

he turned red when i showed him
11/5/2014 7:31:11 PM EDT
[#6]
Sorry about taking this long to answer ya'lls questions.

Yes I had the bolt extended.   This is a new receiver and did not have the gas tube in place. Just trial fitting parts at the moment.

The bolt carrier would not even begin to fit the receiver.

Had a knowledgeable person look at the receiver and he basically said, " It happens ".


Thanks for the replies.



gd



11/5/2014 7:53:24 PM EDT
[#7]
Quote History
Quoted:
Sorry about taking this long to answer ya'lls questions.

Yes I had the bolt extended.   This is a new receiver and did not have the gas tube in place. Just trial fitting parts at the moment.

The bolt carrier would not even begin to fit the receiver.

Had a knowledgeable person look at the receiver and he basically said, " It happens ".


Thanks for the replies.



gd



View Quote


If this is the case, then I would return it to wherever you bought it and get your money back and go buy an upper receiver from a more reputable manufacturer/vendor.
11/5/2014 8:08:46 PM EDT
[#8]
Quote History
Quoted:


If this is the case, then I would return it to wherever you bought it and get your money back and go buy an upper receiver from a more reputable manufacturer/vendor.
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Quote History
Quoted:
Quoted:
Sorry about taking this long to answer ya'lls questions.

Yes I had the bolt extended.   This is a new receiver and did not have the gas tube in place. Just trial fitting parts at the moment.

The bolt carrier would not even begin to fit the receiver.

Had a knowledgeable person look at the receiver and he basically said, " It happens ".


Thanks for the replies.



gd





If this is the case, then I would return it to wherever you bought it and get your money back and go buy an upper receiver from a more reputable manufacturer/vendor.



You are correct Sir !!!!  Returned today.
They sent a return label and away she went.
gd
11/5/2014 8:27:51 PM EDT
[#9]
Quote History
Quoted:
Had a knowledgeable person look at the receiver and he basically said, " It happens ".

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Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.
11/6/2014 12:13:15 AM EDT
[#10]

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Quoted:
Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.
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Quoted:



Quoted:

Had a knowledgeable person look at the receiver and he basically said, " It happens ".







Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.
News to me also.

 



How do you machine a hole that is that much under sized on a CNC machine?
11/6/2014 1:03:23 AM EDT
[#11]
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Quoted:
News to me also.  

How do you machine a hole that is that much under sized on a CNC machine?
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Quoted:
Quoted:
Quoted:
Had a knowledgeable person look at the receiver and he basically said, " It happens ".



Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.
News to me also.  

How do you machine a hole that is that much under sized on a CNC machine?


Type the wrong dimension into the computer?  Load the wrong cutter in the machine?
11/6/2014 1:09:49 AM EDT
[#12]
Quote History
Quoted:


Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.
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View All Quotes
Quote History
Quoted:
Quoted:
Had a knowledgeable person look at the receiver and he basically said, " It happens ".



Not really - unless you're buying from a bottom feeder; I don't think I ever heard of this issue even with Hesse.


We all know stuff happens.  I had a BCM BCG that would not slide smoothly into an Aero Precision upper.  Both companies considered quality manufacturers.  I don't know which part was off, but a quick swap between parts and none of my other parts were incompatible, so I just made sure not use that BCG in that upper.  I also had one of the BCM uppers which would not pin onto multiple lowers.

Sometimes, some magazines will not fit in certain brand lowers, even with some of the better known companies out there.  How about those stripped uppers with unequal side walls a few months back.  As long as the company is stepping up, I don't see what the big deal is.  Stuff happens all of the time.
11/6/2014 3:22:46 AM EDT
[#13]
Tolerance stacking,human error programing CNC mills shit happens.The important thing is how the company responded and they did the right thing,great outcome a place worthy of return buisness
11/6/2014 8:16:10 AM EDT
[#14]
I'm interested in where exactly the upper kept the carrier from entering - charging handle tunnel, or main body diameter?  From OP's description it sounds like it was the main body of the carrier.

I can't see a single error in a keyboard entry causing this.  I can see a screwed up CNC program happening, though.  In particular, the bore of the upper could have been bored incorrectly in a couple of ways, but the diameter?  That's a CNC goof.
11/6/2014 9:55:26 AM EDT
[#15]
Where one happened I suspect there is a whole batch of these out there.
11/6/2014 10:27:01 AM EDT
[#16]
What brand upper?
11/6/2014 3:21:10 PM EDT
[#17]
Since I see that there is still some interest regarding the uppers tolerances let me respond to the best of my knowledge.  Which is limited at best.

GHPORTER asks if it was the main body of the upper.   It was.  Carrier would not /could not fit at all.  Even after trying 4 different carriers.

The charging handle tunnel was fine.  No binding at all.


And as far as the manufacture,  it is Anderson.   But as stated , so far they have stepped up and taken the upper back without any guff.   And I am going to try another of their uppers.  Which should arrive next week.  And I will be checking it out before I get started putting the build together.



gd

11/6/2014 8:18:06 PM EDT
[#18]
Sorry. Buy quality and you won't have to worry about it.
It would make me question everything about it.

Dave N
11/6/2014 8:21:20 PM EDT
[#19]

Quote History
Quoted:


I'm interested in where exactly the upper kept the carrier from entering - charging handle tunnel, or main body diameter?  From OP's description it sounds like it was the main body of the carrier.



I can't see a single error in a keyboard entry causing this.  I can see a screwed up CNC program happening, though.  In particular, the bore of the upper could have been bored incorrectly in a couple of ways, but the diameter?  That's a CNC goof.
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That's what i was thinking too.

 
11/6/2014 9:51:01 PM EDT
[#20]
Quote History
Quoted:
Where one happened I suspect there is a whole batch of these out there.
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That was my thought as well...  Then I had to assume that somewhere along the line, there was a quality control inspection?  How did it get through?  I know the MFG I use inspects...
11/7/2014 11:20:18 AM EDT
[#21]
OP, can you post a comparison pic of the bad one next to a good one?
11/7/2014 11:26:47 AM EDT
[#22]
How was the interior finish of the upper?  Sounds like it got bored, but somehow missed reaming and/or honing.  Regardless, it definitely missed the QC inspection!
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