[Katana16j]

Just wondering if this is a minor quibble or a real problem.

I've noticed residue on the gas lock and surrounding areas after shooting. It seems less accurate now then I remember it being, but it could just be me as a shooter being less consistent.

I'm not sure if it indicates a problem but I thought I would ask. If it is a problem can anyone recommend a fix? Please advise

 

[wiz1997]

Appears to be a gas leak between the barrel and the gas cylinder.

Is the gas cylinder lock on tight?

I had to slip a brass shim between the top of the barrel and the gas lock to seal off a leak around the gas port.

 

[spanky289]

Loose Gas Plug?

 

[BrokenVet]

What does the left side look like?

 

[MemphisMachinists]

Are you leaving some type of oil or anything in your barrel bore or in the gas cylinder? These area's should be clean and oil free. I sometimes leave oil in the bore of a rifle if I think it will not be shot for a while.

 

[art luppino]

Leakage

How many of the parts conerned are commercial parts?

 

[KurtC]

The rear band of the gas cylinder, where the gas port is, looks like it has carbon leaking out. The white stuff up front around the gas lock and castle nut looks more like some kind of chemical (grease? anti-seize?) being baked on.

 

[Katana16j]

To answer some questions:

Its a LRB Barrelled action built by Smith enterprise using USGI parts. I've never removed the gas lock in 10 years of owning it.

Rifle has about 1500 rounds through it, and I've never removed the gas plug (I was under the impression that as long as the piston slides freely when you tilt the rifle the system does not require maintenance).

The left side of the rifle looks the same as the right.

I don't believe I'm leaving any oil or residue in there. I usually clean it with an Otis system, using wet patches with CLP or Hoppes, brass brush, and then more patches until the patch comes out clean and dry.

There is a significant amount of residue in the grooves under the flash hider and on the castle nut.

Could this be caused by resting the forend on a sandbag and covering the weep hole? Would that "Overpressure" the system? I don't see any build up of residue inside the stock though.

I'm probably going to remove the Gas plug and service the gas system, and probably remove and remount the brake.

Any recommendations on that? How tight should the Gas plug be screwed on? On a scale from "Hand tight" to "Bubba'd on with a breaker bar".

Likewise, how tight should the Muzzle brake be affixed? I put the castle nut and gave it like a quarter turn after it seated firmly, I don't want to crank it down too much (unless "as tight as you can get it" is required).

 

[Ted Brown]

It's time to do a little cleaning...

 

[Buelligan]

Rifle has about 1500 rounds through it, and I've never removed the gas plug (I was under the impression that as long as the piston slides freely when you tilt the rifle the system does not require maintenance).

I can't believe it kept passing the tilt test!

 

[KurtC]

Hopefully your gas plug comes out without the use of a bench vise and a breaker bar. RNGR2

It's time to strip everything off and give it a good scrubbing with Hoppes, followed by CLP.

Carbon attracts moisture, which promotes corrosion.

 

[KurtC]

Rifle has about 1500 rounds through it, and I've never removed the gas plug (I was under the impression that as long as the piston slides freely when you tilt the rifle the system does not require maintenance).

That's the rule for immediate maintenance to keep the rifle running. It doesn't apply to "preventive maintenance." You need to clean the carbon out every few hundred rounds or before you store the rifle for a period.