Gas tube discoloration/damage?

>stainless steel so it's not rust

Probably just carbon fouling from the gas block. Wipe it off with Flitz and a rag if it bothers you and you want to polish it, I just shoot it.

You need a new gas tube when your rifle stops cycling properly, until then it's fine.

>>30793904

Yeah, as >>30793965 said, it's normal. I freak at first when I built my first AR, trained on the M4. That post/gas block doesn't do that at all, rebuilt my rifle, after typing the right phrase to find out it's normal as long as block isn't getting loose.

>>30794033
>>30793965
So pretty much the stainless steel look is aesthetics pretty much? I was just caught off guard today because I was doing a deep clean for a long term storage as I will be leaving for college soon. I was worried a little bit that the gas tube was damaged and that it would blow up on me if I didn't get it checked out...again just a freak out as I was not used to seeing this.

Minor discoloration from heat oxidation and possibly getting dusted with gas from the slop of tube-block fitting.

>>30794081
If the gas tube was blowing up, the entire thing would be a weird color because you shot hundreds of rounds through it full auto and fucked up the heat treatment. Some dark staining near the gas block is not how it's going to catastrophically fail. Worst case scenario it gets glued inside your gas block and you have to use penetrating oil like WD40 to soak it and yank out the tube if you ever want to remove it.

The usual replacement schedule is well in excess of 30,000 rounds.

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>>30793904
Been down that road myself. Gas tubes don't form a tight seal with the block. Carbon buildup over time will seal it. In the meantime, you'll have blowback/leakage

>>30794224
Note that the bottom handguard is reversed; the part facing left on the bottom handguard usually faces the gas block. Lot of carbon buildup.

>>30794224
>>30794253
Is there a way to prevent leakage and carbon buildup?

>>30794447
Nope. It's a fact of life. I mean, unless you somehow glue the tube in there, which would be fucking bizarre.

>>30794462
Thanks for the insight. I feel a lot relieved. I was so concerned that I screwed up since I remember lightly putting CLP on the gas tube and barrel for rust prevention. I thought the discoloration was the CLP burning off...

>>30794513
Well, to be fair to your OCD, that may have been a contributing factor; however, the rifle would have done that at least a little bit regardless.

That's normal, gas blocks are leaky but it's accounted for.

If it works, you're fine.

>>30794513
>I remember lightly putting CLP on the gas tube and barrel for rust prevention
WHY
Don't do that.
The gas tube is stainless, and the barrel is probably parkerized or otherwise protected. All you're going to get is a nice coating of dusty, oily filth that smokes all the time when you shoot.

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That straw color could be heat.

It's fine, even if it bursts it's cheap and easy to replace. Gas tubes are pretty tough, they can take a lot more than straw-heat.

>>30793904
saw that baby, bright blue like a motorcycle exhaust after mag dumping about 10 mags through my m16a1. was cooking off rounds about every 2 seconds.