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Posted: 9/14/2013 8:16:14 AM EDT
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So I have a question about buffer tube installation. I don't know where to post in the tech forum so sorry in advance to the mods. So turning the tube in it barley holds the retaining pin but will hold it for sure. one more turn and it runs into the nipple. i have searched and found many people with the same question..almost. what my concern is with the buffer tube installed to where i have it (barley retaining the pin) if i pull back the charging handle with the bcg fully back as far as it can go inside the receiver extension, i notice there is only about 1/8th of an inch of space in between the gas key and the lower receiver. is this going to be ok? will the bumper on the buffer ever wear to a point where the gas key on the bcg could eventually knock into the lower receiver where the receiver extension screws into? like i said i looked on google first but no body asked this perticular question.
thank you very much and im sorry for posting this in the wrong place. |
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it is a bcm receiver extension on a anderson lower. i am not worried about the retainer pin because it is captured well i am concerned about one day the carrier key hitting the lower. right now it is just a hair over an 8th of an inch gap between the gas key and the lower when pulled all the way back. also, when charging handle pulled all the way back the bolt face is about 1/8th to 3/16 behind the rear of the ejection port. i have shot about thousand rounds so far with no issues and just put an h2 buffer in gonna go try it out in an hour or so. i will post pics.
http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1571_zpsa05ea976.jpg on this middle photo you can see the gap between the carrier key and the lower receiver.. http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1566_zpsaf2dd1a3.jpg http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1565_zps94486787.jpg |
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Quoted:
it is a bcm receiver extension on a anderson lower. i am not worried about the retainer pin because it is captured well i am concerned about one day the carrier key hitting the lower. right now it is just a hair over an 8th of an inch gap between the gas key and the lower when pulled all the way back. also, when charging handle pulled all the way back the bolt face is about 1/8th to 3/16 behind the rear of the ejection port. i have shot about thousand rounds so far with no issues and just put an h2 buffer in gonna go try it out in an hour or so. i will post pics. http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1571_zpsa05ea976.jpg on this middle photo you can see the gap between the carrier key and the lower receiver.. http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1566_zpsaf2dd1a3.jpg http://i1288.photobucket.com/albums/b500/spetnaz_soldier/DSCN1565_zps94486787.jpg  what are you asking. DO NOT PUT MONEY IN YOUR GUN. If you have put 1k through your gun without any problems, it sounds like your gun is running fine
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I'm not sure what the problem is, but once in a while you get a receiver and buffer fit situation where the tube is not retaining the pin but another turn of the tube puts it too far forward and interferes with the pin.
In that case, you can file a slight half-moon out of the bottom of the tube where it contacts the pin, and this will allow another full turn of the tube. File only a small amount and test fit until with the tube properly aligned you have proper retention of the pin. As above, DON'T PUT STUFF IN THE TUBE. |
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OP, it's not likely the bolt carrier is going to strike the lower (I've only heard of that when a carbine buffer was used in a rifle tube), but the bolt's position at full stroke and the lack of detent pin capture sure suggest a problem. Try turning in the tube another turn, and maybe filing a little notch like dfariswheel said, to get the fit right, then see where the bolt face lies at full stroke.
Yes, you *can* put washers or quarters in the tube so as to get the stroke right, but I don't like to do it because it's masking the real problem. In this case, I'd suspect the lower's receiver extension threads aren't indexed properly, and the parts are "tolerance-stacking". HTH mully |
| I think you are worrying too much. I never recommend altering the performance of a rifle that is running well based on hypotheticals unless the the likelihood of failure is high, a significant performance gain can be achieved, or it puts safety into jeopardy. If it does one day strike, you have an excuse to get a BCM lower to match that extension. |
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If you have another RE laying around, try it and see if it is the same, or put that BCM in another lower and see if it is the same.
There was a member here a few months ago with this issue, and the lower was out of spec as far as where the detent was drilled. Might reach out to Andersen and see what they say. |
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