Enhanced/Heavy Duty Gas Tubes

[SC-Texas]

I am building an lmg upper for my surefire 100rd mags.

I was interested in a heavier gas tube but it probably isn't a real issue for me.

More like I would grab one if I had a chance.

[sinlessorrow]

There was a video that is now not available to see.

It was from Surefire testing out their 100round mags, they had a gas tube from Colt's IAR(standard material, much much larger) they put 5 of their 100 round mags through the M4 without letting it cool and the gas tube was only red.

The tube showed no signs of sagging, it was a pretty cool video but its been removed.

What I will say is the gas tube bursting generally should not be an issue. If you are dumping mag after mag after mag you probably are not hitting much of anything and just making noise.

[MistWolf]

When the gas tube is glowing red, the metal is in it's plastic state and the tube will be sagging

[sinlessorrow]

When the gas tube is glowing red, the metal is in it's plastic state and the tube will be sagging

I wish the video was still available to better display what I am trying to say about the tube in the video.

[armatac]

I knew the tube was straight for the iar but didn't know if it was thicker or a different alloy, either way because of the heat sink it can handle extended firing schedules better than the M4, once you're that hot different things can happen, like unburned propellants will sometimes fireball the size of your head at your ejection port and its kind of seizure inducing.

[nineteenkilo]

To actually qualify this, there would have to be MTBF testing under extremely rigid conditions to validate any sort of gas-tube-lifespan questions. Under actual scenarios, I suspect they will be infinite or statistically insignificant failures.

Beyond that, the only failures I see in any of this are taking place in fantasy scenarios. I'm not saying it may not have some practical application in an M4. I just can't see it.

Anyone engaging at the rates of fire portrayed here is an asshole. Period. If anyone in my unit had ever done that sort of stupid shit on a two way range, the results wouldn't have been favorable.

The rules are simple. Acquire your target, engage as necessary, repeat.

Anything else is suppressing fire.

No one is capable, IMO, of melting a gas tube with USGI mags in a combat theater. You simply couldn't carry enough ammo or realistically engage targets quickly enough for it to happen. There is a reason that units have 240's and SAWs. Their overbuilt gas tube/regulator/cylinder designs are intended (though rarely ever used) at this rate of fire and can support it. I have personally melted throwaway barrels on both, one right after the other, without any gas issues.

Having said that, thanks for sharing the videos and showing that it is possible and that it may be a potential weakness later down the road. Knowledge is good.

[armatac]

http://www.youtube.com/watch?feature...GOdMPNk#t=171s

great example of about 100 to 150 rounds before a tube failure,
this tube was subjected to many extreme cycles as Jeff is very hard on equipment. This looks more like a blowout than a pure melt.

[Caeser25]

http://www.youtube.com/watch?feature...GOdMPNk#t=171s

great example of about 100 to 150 rounds before a tube failure,
this tube was subjected to many extreme cycles as Jeff is very hard on equipment. This looks more like a blowout than a pure melt.

Necrothread. Would a pencil barrel have any effect on the lifespan of a gas tube since they heat up and cool down faster? I bought a V Sevens inconel gas tube to go with my Faxon 16" pencil barrel, on a whim, thinking it would shorten the lifespan of a regular gas tube.

I was originally only shopping for a titanium buffer retainer, due to a broken one, but needed as gas tube anyways.