WHEN DO WE NEED TO REPALACE A STANDARD GASTUBE?

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Given no FA fire, suspect you'll have no problems w/ a standard gas tube for quite some time. As there have been tests on new outta the box ARs that have run 10,000 semi-auto rounds in a matter of days, ruining the barrel in the process w/ no mention of gas tube problems, I'd say your a long way from problems with one.

Note, I'm guessing here as to what it is your actually asking for, with your vague question.

If your looking for more specifics on alternate gas tube products for differing applications, you'll have to state so in your query.

Mike  

Unless it burst due to automatic fire, or the end is bent/worn out by the carrier key, Never.

But during cleaning, add a few drop of CLP down the tube (from the receiver end) to allow the CLP to dissolve any fouling (and free any brass flakes that may be stuck to the gunpowder fouling) from inside the tube.  Don't worry about the CLP left in the gas tube, the first time you fire the rifle after cleaning, the barrel pressure will just blow back all the dissolved fouling/flakes into the carrier gas section, where you can just remove it during you next cleaning.

The gas rings and gas tube at the end that fits into the carrier key are designed to wear out... eventually... The when has a lot of variables... ammo used, rate of fire, cleaning/maintenance practices, proper alignment of the gas tube/carrier key...

Don't stick any thing into the gas tube to 'clean' it... The real reason most gas tubes are replaced I'd bet, a pipe cleaner stuck in it... Just watch the carrier key end for wear.  I do keep several tubes on hand as part of my parts stash but have never 'needed' to change one out due to wear or cycling problems, even on my high mileage AR's... Just wanting to change one out is different... [;)]

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