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10/14/2010 6:01:19 PM EDT
Just got my upper in the mail... BCM Upper with a BCM BCG.

The BCG came with a little tiny o-ring that's maybe 1/4 an inch in diameter.  Where does it go?
10/14/2010 6:04:48 PM EDT
[#1]
That goes around the extractor spring to increase the extractor's holding power. I'm not sure if you need it though.
10/14/2010 6:05:35 PM EDT
[#2]
Just save it for later use.
10/14/2010 6:10:08 PM EDT
[#3]



Quoted:


That goes around the extractor spring to increase the extractor's holding power. I'm not sure if you need it though.


+1



Take it to the range first.  If all goes well - no need to install the O-ring.



 
10/14/2010 6:18:28 PM EDT
[#4]
Quoted:
Just got my upper in the mail... BCM Upper with a BCM BCG.

The BCG came with a little tiny o-ring that's maybe 1/4 an inch in diameter. Where does it go?


In your spare parts box.
10/14/2010 6:20:00 PM EDT
[#5]
oops.
10/14/2010 6:47:04 PM EDT
[#6]
I've never installed mine and I shoot steel cased ammo exclusively now. Not needed, at least for my rifle. Yours may be different.
10/14/2010 6:51:50 PM EDT
[#7]
You say it's not needed... but is there any reason why I wouldn't want to put it on?
10/14/2010 6:58:32 PM EDT
[#8]
The o-ring increases extractor tension. I wouldn't use it unless I had weak extraction issues.

Too much extraction can cause timing issues and lead to malfunctions, not to mention the o-ring could break and gum up something inside the rifle.
Thousands of people use the o-ring, thousands do not. Its like deciding to use an Accuwedge (how ever its spelled).
10/14/2010 7:01:04 PM EDT
[#9]
I have never used an o-ring and have never had problems with extraction...

Reason for not using:

It will break at an unpredictable round count and gum up the works.




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