AR-15 gas tube question

[twadsw01]

Is the AR-15 gas tube supposed to be a little loose inside the receiver where it comes through to the gas key on the BCG?

I was cleaning the rifle last night and when I put some patches and a toothbrush down in the charging handle raceway towards where the gas tube comes through the front of the receiver, I noticed that the gas tube had a little bit of play in it (couldn't see it moving when touched, but could hear it moving around inside of the hole through the receiver above the barrel). Is this the way it's supposed to be?

If so, what keeps the gas inside the receiver that is impinging on the BCG from escaping back out the front of the receiver through the small gap around the gas tube? Seems like there should be some sort of gasket or something there to seal things off. But, I have no idea what I'm talking about.

 

[tuckner]

Re: AR-15 gas tube question

If it's still pinned to the gas block and cycling you are fine.

 

[twadsw01]

Re: AR-15 gas tube question

Okay. Yeah, it works perfectly, no problems at all. Fired it for the first time last night. It's a beautiful thing.

 

[Anchor Zero Six]

Re: AR-15 gas tube question

The end of the gas tube should have a bit of a flared ball shape to it. This acts as a seal of sorts inside the bolt carrier key.

As for gas leakage, I regret being the first to tell you this but AR's blow gas all over the inside of the receiver. In the operation sequence the gas tube is inside the BC Key untill the BCG begins traveling rearward at which time gas is expended inside the receiver and often back through the charging handle and anyplace else it can go.

 

[twadsw01]

Re: AR-15 gas tube question

Yeah man. I knew that they blew it all over the inside of the receiver, but I didn't know what kept the gas from leaking back out through the port that the gas tube comes IN to the receiver through.

Gotcha. Thanks for the explanation.

 

[tuckner]

Re: AR-15 gas tube question

It will throw gas out that receiver hole, but it has no impact on anything related to the weapons function, at that point the BCG is already running it's course.