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9/20/2009 9:23:22 AM EDT
I put together my first sbr and it's having trouble ejecting/feeding ammo. I've done about all the troubleshooting I know (new magazines, h buffer, upgraded extractor) and I was wondering if there is a good company who can troubleshoot and get my gun running reliably. I saw specialized armament has reliability packages but I think they only work on colts.

Fwiw I'm running a cmmg upper with bcm 11.5 barrel and dd bcg on a rr lower.
9/20/2009 9:36:43 AM EDT
[#1]
Need more info on how exactly it is malfunctioning.
9/20/2009 9:59:41 AM EDT
[#2]
I'm having multiple failure to extract malfunctions which leads to double feeds. My bolt will lock to the rear on an empty magazine.
9/20/2009 10:44:53 AM EDT
[#3]
Fired casing stays in the chamber? I know you mentioned that you tried an H buffer, but have you tried heavier? H2, H3, 9mm buffers?
9/20/2009 12:54:52 PM EDT
[#4]
Yes, the fired case stays in the chamber and no i haven't tried any other buffers.  Thus the reason for my question.  Im not interested in buying another hundred bucks worth of buffers in the chance they may work.  I would like to find a company or person who can trouble shoot for me so i dont buy a bunch of parts that may or may not work for me.  I want to carry this rifle on duty so i need to make sure its reliable and i think ive dont about all i know to do.

9/20/2009 1:02:05 PM EDT
[#5]
sounds like your extractor doesnt have enough grip.  What type of extractor upgrades did you do?
9/20/2009 1:09:55 PM EDT
[#6]
Quoted:
Yes, the fired case stays in the chamber and no i haven't tried any other buffers.  Thus the reason for my question.  Im not interested in buying another hundred bucks worth of buffers in the chance they may work.  I would like to find a company or person who can trouble shoot for me so i dont buy a bunch of parts that may or may not work for me.  I want to carry this rifle on duty so i need to make sure its reliable and i think ive dont about all i know to do.



Then post in your hometown forum to see if anybody has various buffers that can help you out.

The basic problem sounds like excessive gas. The bolt is unlocking too early and your extractor is unable to pull the case out of the chamber while there is still a relatively large amount of pressure in the system. A heavier buffer will hold the bolt closed longer so that the pressure can drop to allow extraction.
9/20/2009 1:10:01 PM EDT
[#7]
I put on the BCM upgraded extractor spring.  I didn't use the provided O ring, maybe that is something else to try.  Although to be perfectly honest i dont know where it goes.
9/20/2009 1:18:38 PM EDT
[#8]
Quoted:
I put on the BCM upgraded extractor spring.  I didn't use the provided O ring, maybe that is something else to try.  Although to be perfectly honest i dont know where it goes.


This may be your problem. That O ring slips over your extractor spring. The inside of your O ring should be the same diameter as the extractor spring.
But like the previous post have said you may need a heavier buffer.
9/20/2009 1:38:15 PM EDT
[#9]
Install the o-ring & report back after the next range trip.
9/20/2009 4:17:35 PM EDT
[#10]
The o-ring will likely increase your reliability greatly.  If you have a heavier buffer slip that into the mix as well.  A receiver extension spring upgrade is always a plus, such as the Superior Shooting Systems flatwire spring.  At this point you want to try to slow your action down as much as possible to keep it reliable with crappy ammo like wolf.
9/20/2009 4:25:19 PM EDT
[#11]
Put the factory buffer back in. An H buffer is more resistance, which is probably only magnifying the problem...
9/20/2009 5:59:31 PM EDT
[#12]
If you want to send it to me I can trouble shoot it for you. Just cover the shipping, and parts if need be.
9/20/2009 8:23:41 PM EDT
[#13]
Quoted:
If you want to send it to me I can trouble shoot it for you. Just cover the shipping, and parts if need be.



Hmmmm....wow!

9/21/2009 3:44:38 AM EDT
[#14]
Quoted:
Put the factory buffer back in. An H buffer is more resistance, which is probably only magnifying the problem...


Thats an offer too good to turn down.  Can you shoot me an email or pm on where it needs to go??
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