AR Question

What you are describing is not uncommon with the short barrels. My experience has told me that "beefing" up the extractor spring, with either a stronger spring, D ring, or whatever, will assist and fix the problem. The bottom line is getting the extractor strong enough so that it is very stiff to the point of being hardly able to move while positioned in the bolt.
 
koldt said:
What you are describing is not uncommon with the short barrels. My experience has told me that "beefing" up the extractor spring, with either a stronger spring, D ring, or whatever, will assist and fix the problem. The bottom line is getting the extractor strong enough so that it is very stiff to the point of being hardly able to move while positioned in the bolt.

+1

i had the same problem with my 7.5" upper and i used an extra power extractor spring, and a "H" buffer which has some more weight to it. now it runs like a champ, too bad its a safe queen now...:D
 
I've seen guys even cut out some rubber/plastic bits to fit the area to beef up the extractor and augment the spring. Kinda mickey mouse, but it worked. The "D" rings are just that, a small rubber D ring to fit just outside the extractor spring to fit between the extractor and the bolt while remaining inside the extractor cutout/slot inside the bolt.
 
If you know anyone/anywhere that may have a supply of extractor spings, they are never the exact same length. Just look through the pile and pick out the longest one you can find. Some guys also put a small piece of rubber inside the spring, if they can fit it in. There was the factory Colt blue coloured rubbers, but I found they actually didn't do much.
 
Yeah LMT is good..My LMT 10.5 has never had a jam with almost 1K rounds through it.. But the pig sure gets dirty. The extractor is very stiff.
 
I built two 7",
one with Pigtail, one without.

Both were reliable,
BUT,
I used a full length buffer and spring with an ACE skeleton stock.
 
Forget about the pigtail, not required and may make things worse.

Like has been mentioned this is probably an extraction issue, check the spring under the extractor, it should have a black rubber insert inside it. If the insert is dark blue, or missing, than replace it with a black one. While you're at it you may as well upgrade the spring to an extra strong or CS spring. Not sure who stocks CS springs in Canada, I wouldn't mind picking some up to replace my extractor and ejector springs.

As for the Defender, you can give that a try if the above doesn't work, or you could use a Crane 0-ring.

ETA: Since this is a cut down than the real problem may lie in the size of the gas port. Take it to a smith who has a lot of experience with AR's and have him measure the diameter, he may need to open up the size of the gas port to make it run reliably.
 
Last edited:
Leg said:
Forget about the pigtail, not required and may make things worse.

Like has been mentioned this is probably an extraction issue, check the spring under the extractor, it should have a black rubber insert inside it. If the insert is dark blue, or missing, than replace it with a black one. While you're at it you may as well upgrade the spring to an extra strong or CS spring. Not sure who stocks CS springs in Canada, I wouldn't mind picking some up to replace my extractor and ejector springs.

As for the Defender, you can give that a try if the above doesn't work, or you could use a Crane 0-ring.

ETA: Since this is a cut down than the real problem may lie in the size of the gas port. Take it to a smith who has a lot of experience with AR's and have him measure the diameter, he may need to open up the size of the gas port to make it run reliably.


By all means try to beef up your extractor, but I agree that the problem is likely to be with the size of the gas port. I was actually discussing the idea of shortening AR15 barrel lengths with 2 guys that I work with last week. They're gunsmiths, who've done a lot of governemnt sponsored experimenting with barrel lengths. They found after cutting 16" barrels down to 10.5", they had a lot of gas stoppages. After reaming the gas hole, it wasn't a problem any more. So keep that in mind if the extractor doesn't work
FYI, with the same tests, on 11.5" barrels, they had considerably less problems, but reamed the gas ports anyways.
 
Lordco has a nice selection of rubber O-Rings that just happen to be the same size as the "D-Ring" ;) - Go to Lordco with your extractor spring in hand and find the O-Ring that goes around it and buy a few.
 
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