Gas System Problem?

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[ARCHIVED THREAD] - Gas System Problem?

Posted: 2/20/2006 3:45:17 PM EDT

I've got a Bushy M4 I've had for about 4 years now. I've had several thousand rounds through it without a single FTF or FTE. Until about 6 months ago. I was at the range and kept having a spent casing not completely eject, while the new round would get stuck on the way into the chamber. A pain in the ass to clear. It also left a really big gouge in both casings. I thought it was an extraction problem so I replaced it with a defender ring. No change. I've tried different ammo and different mags. I just sprayed some CLP down the gas tube until it started leaking out the end of the barrel. Mopped it really well with some pipe cleaners, all of which came out clean. I hope to try it again next weekend, but any other thoughts before I go again?

ETA: The gas rings on the carrier seem to be in good condition, someone recommended standing it on end and if it held it's weight they were still good.

Posted: 2/20/2006 6:09:21 PM EDT

[#1]

Do a short stroke test.

From the troubleshooting sticky:

"---TEST FIRING PROCEDURE---
-Unload the rifle and verify that it is clear.
-Check the bore for obstructions.
-Load the rifle with one round from the magazine. Use quality ammunition and a proven magazine for this.
-Aim downrange and fire, the bolt should catch on the bolt stop. Hold the rifle as loose as possible.
-Reload and repeat the process if the rifle does not lock open Depress the bottom of the bolt stop before firing this time. This allows for weak magazine springs, sticky followers, or an overly strong bolt catch spring.
-If the bolt does not lock open then there is a gas system problem. Investigate and repair the problem.
-If it only locks open with the bolt stop depressed, repeat the process with a different magazine. If the rifle still fails to function then look at the bolt stop as a probable culprit.

Posted: 2/20/2006 7:48:20 PM EDT

[#2]

Bushy=check the key screws to make sure that they are still tight (35 in lbs).

Posted: 2/20/2006 8:03:35 PM EDT

[#3]

Quoted:
Bushy=check the key screws to make sure that they are still tight (35 in lbs).

Ding.

Posted: 3/1/2006 12:57:05 PM EDT

[#4]

Quoted:
Bushy=check the key screws to make sure that they are still tight (35 in lbs).

Dumb question, but how do I verify 35 in. lbs on an allen screw?

Posted: 3/1/2006 1:13:06 PM EDT

[#5]

Quoted:
Quoted:
Bushy=check the key screws to make sure that they are still tight (35 in lbs).

Dumb question, but how do I verify 35 in. lbs on an allen screw?

With a torque wrench. Duh!

But just get them good and snug. Not so tight you snap off the head, but not loose. If you can tighten them at all, they were loose.

Posted: 3/1/2006 5:14:08 PM EDT

[#6]

Check your ejector. Push in on the ejector. Does it move without binding? If not you may need to remove the ejector and spring and clean both and the hole the spring/ejector fits in. The case is being extracted from the chamber, so it's not an extractor problem. If it is not short stroking, the ejector may be the answer.

Posted: 3/1/2006 7:25:00 PM EDT

[#7]

I have seen the same malfunction you are experiencing happen because of the bolt plunger being obstructed by brass shavings. Perhaps worth checking.

[ARCHIVED THREAD] - Gas System Problem?

AR-15 » Troubleshooting

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