Rifle +3 & +4” gas tubes

Longer has systems have been believed to have less felt recoil. They have less dwell time as well, which leads to lower pressures and port noise. Some speculation as to making it run cooler as well.

It could make your rifle not like a particular load that was good functional wise in another rifle though.

+3 is plenty honestly +2 even is fine at 22"

I have not, but I don’t keep up with much of that. Once you get so close to the muzzle, you start regurgitating history and the dissaptor setups. They have been around for a long time, didn’t take off as far as popularity but still around.

A well built ar with a rifle length system works just fine in all my dealings with ar platforms. Not as extensive as some around here they will be around to talk shortly I’m sure.

Are you talking about one of those gas tubes that looks like a crazy straw?

Im2bent said:

Are you talking about one of those gas tubes that looks like a crazy straw?

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Those are called pigtails and I had one for a short 7.62x39. They are supposed to make a pistol length system behave like a carbine length. I still have it at the house, never ended up using it. They need a fairly large ID handguard to support

+2 is fine imo with a 26"

roostercogburn98 said:

I have not, but I don’t keep up with much of that. Once you get so close to the muzzle, you start regurgitating history and the dissaptor setups. They have been around for a long time, didn’t take off as far as popularity but still around.

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What do you mean?

Cascade Hemi said:

What do you mean?

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The dissipator rifle has been around for a long time. Iffin I’m not mistaken, the point of that design was to push the gas system as long as possible to help with dwell time and port pressures.

I guess my statement was that the idea plus length gas systems is not new. It just seems to have a little more following and aftermarket input than the dissipator style ever got.

232593 said:

I have a 26” 22 CM Bartlein barrel on order. As I understand it one should get as long as a gas tube as possible with this combo. Longest I have seen advertised is +3. I have heard members on this forum mention a +4. Who makes those?

Also, can a really long gas system like that cause other problems?

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Longest I saw was white oaks +3. I would think that would be sufficient. Doubt you would notice the extra 1" if you could find the +4. Better question is what size gas port would you run with the rifle +3 setup?

Agree with no reason to hunt down a +4. +2/+3 would be plenty IMO. Did you reach out to Bartlein to see what they recommend for their barrel/port size?

roostercogburn98 said:

The dissipator rifle has been around for a long time. Iffin I’m not mistaken, the point of that design was to push the gas system as long as possible to help with dwell time and port pressures.

I guess my statement was that the idea plus length gas systems is not new. It just seems to have a little more following and aftermarket input than the dissipator style ever got.

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The Dissipator was a carbine length gas system with the A frame sight mounted rifle length.

Cascade Hemi said:

The Dissipator was a carbine length gas system with the A frame sight mounted rifle length.

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The dissy was a 16 inch barrel with a rifle length gas. Essentially a plus length gas system for a carbine length barrel.

Cascade Hemi said:

The Dissipator was a carbine length gas system with the A frame sight mounted rifle length.

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roostercogburn98 said:

The dissy was a 16 inch barrel with a rifle length gas. Essentially a plus length gas system for a carbine length barrel.

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No it wasn't, "Dissipator" was a registered trademark of Bushmaster. It was only ever produced in a carbine length gas system. Your picture is incorrect and isn't a Dissipator, Colt's experimental 605 versions were cut down 20" rifle barrels and would have had lightweight profiles. Colt never sold them though and they weren't Dissipators. In the early '00s companies like CMMG sold Dissipator clones, they were also carbine length gas systems. Since then, who knows but the name Dissipator meant Bushmaster and carbine length gas system.

Cascade Hemi said:

No it wasn't, "Dissipator" was a registered trademark of Bushmaster. It was only ever produced in a carbine length gas system. Your picture is incorrect and isn't a Dissipator, Colt's experimental 605 versions were cut down 20" rifle barrels and would have had lightweight profiles. Colt never sold them though and they weren't Dissipators. In the early '00s companies like CMMG sold Dissipator clones, they were also carbine length gas systems. Since then, who knows but the name Dissipator meant Bushmaster and carbine length gas system.

What is an AR-15 Dissipator & What Is It Used For?

Learn what exactly is an AR-15 dissipator, its pros/cons, whether the design is still useful in this day and age, and recommended models.

www.pewpewtactical.com

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The picture I attached came from the same article you posted. It even labels the barrel as a dissipator.

roostercogburn98 said:

The picture I attached came from the same article you posted. It even labels the barrel as a dissipator.

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I have no idea which was first or correct but what he says about the Bushmaster guns is what I remember as well. I've seen barrels set up like your picture but the bushmaster stuff is where I first saw it.

AMMOWASTER said:

I have no idea which was first or correct but what he says about the Bushmaster guns is what I remember as well. I've seen barrels set up like your picture but the bushmaster stuff is where I first saw it.

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Could have been bushmaster, or maybe way back Vietnam time when they cut down the colts like he said as well.

My point was that the concept wasn’t new. They have toyed with reducing dwell time and port pressures since the 60s.

The article he quoted saying I was wrong is the same article that had the picture of the barrels I posted.

OP has settled on a gas system so it’s a moot point anyway imo.