AR-15 + suppressor problems

[Clhallmet]

Hello all,

About a year ago I received my stamp and suppressor. I shot suppressed and non suppressed off and on during a few outtings with no problem. Recently the rifle will only cycle properly when the suppressor is attached. While unsuppressed the bolt cycle sometimes far enough back to eject but not feed the next round. Sometimes it wont even eject them.

Trying to solve the issue I have cleaned the rifle gas components like crazy, even to the point of running pipe cleaners done the gas tube. I have removed the gas block and brushed the port and the hole in the barrel as well(the holes were aligned) . I have cleaned the bolt carrier and have checked the rings multiple times. I have also brushed the gas ports in the carrier as much as possible. And I'm getting a solid seal with the gas system(not much leaking at all with the carrier locked forward). Also the buffer and spring are clean and aligned

I have no idea what else to do to get this thing working right again. I have been told to drill out the barrel port bigger and add an adjustable block. But is this necessary if it worked properly before this happened?

Thanks in advance.

 

[spife7980]

New ammo?
You said you cleaned it but is it lubed or dry?

 

[supercorndogs]

Loose or leaking gas key, leaking gas tube, leaking gas rings. Did you replace the gas rings or just look at them?

 

[Clhallmet]

New ammo?
You said you cleaned it but is it lubed or dry?

All hand loads, I used my magneto speed and got around 3130fps with consistent speed and results.

 

[Clhallmet]

Loose or leaking gas key, leaking gas tube, leaking gas rings. Did you replace the gas rings or just look at them?

I checked the leaking by putting a spent shell in the chamber. Then I sprayed soapy water at the gas block, where the gas tube entered the receiver and on the carrier. I then blew air into the barrel at pretty good pressure and maintained the pressure. The only leaking I saw was minimal at the block and where the tube enters the receiver. Nowhere else.

 

[Mac679]

Stand your assembled bolt carrier on the bolt face with the bolt extended in the unlocked position. The gas rings should support the weight of the carrier without collapsing to the locked position. If they do collapse, you need to replace your gas rings.

 

[Clhallmet]

All hand loads, I used my magneto speed and got around 3130fps with consistent speed and results.

Stand your assembled bolt carrier on the bolt face with the bolt extended in the unlocked position. The gas rings should support the weight of the carrier without collapsing to the locked position. If they do collapse, you need to replace your gas rings.

I forgot to mention this but have tried this with passing results as well. It's weird though, it wasn't a gradual occurring issue. It just started out of nowhere and has continued doing it ever since.

 

[Huskydriver]

Stand your assembled bolt carrier on the bolt face with the bolt extended in the unlocked position. The gas rings should support the weight of the carrier without collapsing to the locked position. If they do collapse, you need to replace your gas rings.

This^^^. Sounds like you are loosing pressure somewhere in the system and the most likely culprit is probably a leaky gas key or shot rings. What kind of trigger and barrel are you using? Would def highly recommend an adj gas block because you fine tune your gas to run optimally with the can on. I use superlatives across the board on all my ar's

 

[Clhallmet]

This^^^. Sounds like you are loosing pressure somewhere in the system and the most likely culprit is probably a leaky gas key or shot rings. What kind of trigger and barrel are you using? Would def highly recommend an adj gas block because you fine tune your gas to run optimally with the can on. I use superlatives across the board on all my ar's

I have recently installed the fostech echo trigger and put in an "palmetto" (or so I was told) M-16 carrier group for which it requires. I've also swapped the bolt out of my m&p carrier to the m16 carrier to see if it was possibly the rings. Same result. I haven't on the otherhand pressure checked the gas key with the carrier out of the receiver. I suppose ill try that next to see if I need a new key.

 

[oldfatguy]

M-16 bolt carrier group is probably heavier then the original. You might try a lighter buffer to see if increased weight is your problem.

OFG

 

[Huskydriver]

Had a similar issue when building a new ar for a guy with a new elf trigger with the new half cock feature. I normally tune down the block to where it just barely cycles unsupressed then dial the block back a couple clicks so it will cycle reliably unsupressed. The rifle ended up a full turn more gas than any other system I have used these components on so best I could figure the resistance from this elf trigger required more gas pressure to overcome in order to cock eject then feed the next round. If you don't have an adjustable block and everything else checks out I would start there. Your barrel may have a slightly underspec gas port and with carbon fouling, has closed just enough with a standard block you are low on pressure.

 

[AMP!]

I’d start by replacing one part at s time to the originals you were running. Try the old carrier group, see if anything changes. Then trigger, etc.

If the rings are good and it’s not leaking, I think this is the best way to find the issue.

 

[Peterpan]

Sadly it just sounds like a process of elimination deal like before mentioned.