View Full Version : Need help from the brain trust here
So I have assembled a handful of AR’s over the years, but never really had to trouble shoot one before. A coworker of mine asked me to look at his AR that won’t eject. I took it to the club today and it won’t eject at all. I changed out the BCG and mag for the one out of my AR I had with me that works fine, still no dice.
Now, it is a DPMS rifle. I know they’re junk, but I used to have one that ran fine. Any ideas? Thanks in advance for any advice.
So I have assembled a handful of AR’s over the years, but never really had to trouble shoot one before. A coworker of mine asked me to look at his AR that won’t eject. I took it to the club today and it won’t eject at all. I changed out the BCG and mag for the one out of my AR I had with me that works fine, still no dice.
Now, it is a DPMS rifle. I know they’re junk, but I used to have one that ran fine. Any ideas? Thanks in advance for any advice.Will it extract and then fail to eject? Could use a little more info to help.
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After each shot. The BCG would be in the forward position. When I racked the BCG the empty would come out and when I let the BCG go forward it would load another round. It’s a single shot right now.
I forgot to add that I also changed out the recoil spring and buffer, didn’t help.
Also the chamber is clean.
Renegade04
11-05-18, 14:10
Headspace issue maybe?
If the bolt isn't moving during the firing sequence it sounds like a gas issue. Has it ever worked? I mean, sounds crazy but maybe the gas port wasn't drilled in the barrel or something dumb like that.
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If the bolt isn't moving during the firing sequence it sounds like a gas issue. Has it ever worked? I mean, sounds crazy but maybe the gas port wasn't drilled in the barrel or something dumb like that.
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I’m asking him now.
So I just discovered that the gas block is loose and will slide up and down the barrel. Lol
So I just discovered that the gas block is loose and will slide up and down the barrel. LolYeah, that will do it.
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It looks as if the Allen screws were never tightened. They were backed all the way out.
I’m going to loctite them and see if it’ll run now.
If you haven’t already, before you do that, check to see if the barrel has dimples. If not, dimpling will go a long way in helping fix the issue.
It looks as if the Allen screws were never tightened. They were backed all the way out.
I’m going to loctite them and see if it’ll run now.
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If you haven’t already, before you do that, check to see if the barrel has dimples. If not, dimpling will go a long way in helping fix the issue.
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Dimples aren't necessary with the right screws. At least not on a square range rifle.
Let me guess? Is this an Oracle model with the aluminum picatinny gas block? The issue with that gas block, is not only is the barrel not dimpled, but it also made from aluminum.
It looks as if the Allen screws were never tightened. They were backed all the way out.
I’m going to loctite them and see if it’ll run now.
If you haven’t already, before you do that, check to see if the barrel has dimples. If not, dimpling will go a long way in helping fix the issue.
Dimples aren't necessary with the right screws. At least not on a square range rifle.
What you want to use is a knurled point/ knurled cup point setscrew; even if using the knurled cup point set screw it is best to make a dimple large enough that the setscrew can begin to enter into the dimple.
If you need a definition of what a knurled cup point is, here you go: https://en.wikipedia.org/wiki/Set_screw
One of the problems is that the hardware stores in my area stock plain cup points, I go to an industrial supply place to get knurled cup points.
The knurled cup points shouldn't be reused, although if the barrel is dimpled and the set screws are secured using blue loctite, it probably doesn't make much difference.
If the gas block is aluminum (use a magnet to check if you are unsure) you might want to replace it with a carbon steel one. These are my go-to: https://algdefense.com/carbon-steel-gas-block.html Of course if you need a pic rail gas block they won't fit the application.
Red Loctite should always be used for gas block set screws.
What you want to use is a knurled point/ knurled cup point setscrew; even if using the knurled cup point set screw it is best to make a dimple large enough that the setscrew can begin to enter into the dimple.
If you need a definition of what a knurled cup point is, here you go: https://en.wikipedia.org/wiki/Set_screw
One of the problems is that the hardware stores in my area stock plain cup points, I go to an industrial supply place to get knurled cup points.
The knurled cup points shouldn't be reused, although if the barrel is dimpled and the set screws are secured using blue loctite, it probably doesn't make much difference.
If the gas block is aluminum (use a magnet to check if you are unsure) you might want to replace it with a carbon steel one. These are my go-to: https://algdefense.com/carbon-steel-gas-block.html Of course if you need a pic rail gas block they won't fit the application.
A buddy needed help with a DPMS before. He ended up dumping the quad rail and aluminum gas block, and replacing it with a AGB and 10" used ALG rail. The AGB fixed the overgassing, and he lightened up the front end quite a bit. It's his square range barrel burner, which he realizes. He bought it before he knew any better, and has since built a better rifle as a go-to.
Red Loctite should always be used for gas block set screws.
Geiselle says blue in their instruction for the Super Gas Block, that is what I was going off of since I use those gas blocks.
Not sure why, but at BCM we used red and at SIONICS we use it as well. So do a few other companies.
Geiselle says blue in their instruction for the Super Gas Block, that is what I was going off of since I use those gas blocks.
Not sure why, but at BCM we used red and at SIONICS we use it as well. So do a few other companies.
Would rocksett not be equal or better for this job since it can handle higher heat than loctite?
I have yet to see properly Loctited screws come loose. With that said, should you need to remove it, heat works. With Rocksett you would need to submerge it in water.
Would rocksett not be equal or better for this job since it can handle higher heat than loctite?
It’s not my rifle so I’m not too concerned with durability. I don’t think my friend is either since he bought a $400 AR. He told me he bought it New a few years ago and only shot a few rounds through it because it stopped working. So I don’t ever see him running it hard. I will try to talk him into getting a better gas block or a better rifle, but I’m pretty sure he won’t heed my advice. I’m pretty sure it is an Oracle. The barrel was dimpled FWIW. I just tightened them down and used a lot of Red Loctite.
I have yet to see properly Loctited screws come loose. With that said, should you need to remove it, heat works. With Rocksett you would need to submerge it in water.
I’ve only owned Red loctite. I use it on Glock front sights and such. I’ve never used it on an AR beings that I prefer pinned gas blocks. I’ve never had an issue getting it off using heat.
Please read what I posted.
I’ve only owned Red loctite. I use it on Glock front sights and such. I’ve never used it on an AR beings that I prefer pinned gas blocks. I’ve never had an issue getting it off using heat.
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