AR15 AR10 Lengthen gas tube only?

[Kocher]

Those that have ever tried to run an A.R. 10 and have used other than the low pressure NATO caliber knows what I’m talking about.

I’m talking dwelltime , more importantly delaying unlock.

what would happen if you double the length of the gas tube only?

I’ve included a very quick sketch so it’s perfectly clear what I’m talking about...

Will this work and delaying the unlock time so that the powder can all be burnt before your BCG attempts to extract the case and you get maximum charge without destroying your case.

 

[Austan]

Do they make a pigtail gas tube for ar10's? Isn't that what they are for?

 

[Kocher]

I don’t know I’ve never seen anything like that?
do you have any pictures of it?

 

[Kocher]

I thought about even doing something electrical fashion, that would get rid of the gas tube/system entirely. But I thought I would throw this idea out there and see if this is even an option. A much simpler option if it would work.

 

[Kocher]

OK I found what you’re talking about but it looks like it will not be long enough for the plus to gas system on my particular rifle but apparently that’s a better idea you just run a loop around the barrel pretty simple.
Apparently it worked for one of them

 

[Austan]

It looks like this. I don't know if someone makes one for longer then pistol length but I'm sure a person could make their own with enough motivation.

Pigtail Gas Tube KM Tactical AR 15 AR 308 Pistol SBR

Pigtail Gas Tube Pigtail Gas Tube Product Specs: Extends your pistol gas system to carbine length Softer Recoil Impulse Prevents Cycling Issues In Pistol Length Systems Lengthens Gas Pressure To Prevent Bolt Bounce, Feeding Jams, And Short Stroke J

kmtactical.net

 

[2aBaC̶a̶]

and you cant accomplish the same with AGB, adjustable BCG, or adjusting the Buffer weight and spring?

 

[newguy2k3v2]

I remember seeing a pic of a pigtail gas tube that had several could around the barrel on a wsm upper somewhere.

The best option is proper port placement. That's why rifle +2" gas systems have become so common with 6/6.5 gas guns. Adjustable gas block. A heavier buffer and BCG should slow unlocking a bit as well.

 

[Kocher]

Someone please tell me about "Pig Tail" gas tubes.

I have heard mention and seen pictures of something called a "Pig Tail" gas tube, usually in relationship to SBRs with 10" and shorter. The story seems to be that this type of gas tube helps an SBR gas system act like a longer one. If this is true I am wondering if there is one that will "lengthe...

ar15armory.com

in this post it does talk about the pigtails but relation to a SPR I’m talking about for rifle length even a +2 length gas tube and it still is not enough I think that this simple double tubing length may even do better.

Because all it’s doing is slowing down that impulse, and the unlocking of the bcg, that’s all I needed to do.

 

[Kocher]

Stronger buffer springs, heavier buffer’s and adjustable gas block had NO effect on many of the cartridges that I’ve seen.

A prime example of it having no effect is with the 22nosler Ar15 round.
look at Johnny’s reloading bench on ytube and you’ll find plenty information and all the different things he tried to do to correct the cases from being destroyed. Aside from running it like a bolt action= no effect on case life.

 

[Kocher]

I think this simple actually quite frankly very inexpensive fix is worth a try it seems perfect sense to me that it would work.
SLow down the impulse=lengthen the time from bullet passing the gas tube port and gives milliseconds, to allow:
1.Slower powders to be used
2.Heavier Bullets to be used
Extend case life so you can reload more than once.

 

[Kocher]

I remember seeing a pic of a pigtail gas tube that had several could around the barrel on a wsm upper somewhere.

The best option is proper port placement. That's why rifle +2" gas systems have become so common with 6/6.5 gas guns. Adjustable gas block. A heavier buffer and BCG should slow unlocking a bit as well.

None of those slow down the “Attempt”
to pull the bcg open. At least my understanding it’s still attempts to open and it just requires more gas before it will operate. Not the same as having a longer gas tube Or at least that’s my understanding.

 

[Huskydriver]

+2" gas and a agb done

 

[TonyTheTiger]

A prime example of it having no effect is with the 22nosler Ar15 round.

That just sounds like the notoriously shitty brass doing what notoriously shitty brass does.

 

[newguy2k3v2]

What kind of oddball setup are you trying to run if you've got a spr(assuming 18" barrel) and a rifle +2" gas system already?

I have a 24" 6.5cm with a rifle length gas system. Almost notoriously rough on brass. A FA carrier, adj gb and 8.5oz buffer cured all my brass damage issues. A +2" system and lighter components would be better but I'm going to run this one until it won't shoot anymore.

 

[Expert684]

Adjustable gas block cured my problems.

 

[Jigstick]

Couldn’t you just make the gas tube real fat in OD with it necked down on the ends ? Double or triple the volume of the gas tube?

 

[srt-4_uk]

Or just, you know, make less gas go into the gas tube so it takes longer to fill up.

 

[2aBaC̶a̶]

Curious as to what effect an adjustable volume gas block would have.

 

[Ravenworks]

OP, do you understand what you're asking or talking about?
What system do you have?
Carbine
Mid-length
Rifle

 

[Jigstick]

I have a coiled gas tube on my plasma rifle

 

[LRRPF52]

Those that have ever tried to run an A.R. 10 and have used other than the low pressure NATO caliber knows what I’m talking about.

I’m talking dwelltime , more importantly delaying unlock.

what would happen if you double the length of the gas tube only?

I’ve included a very quick sketch so it’s perfectly clear what I’m talking about...

Will this work and delaying the unlock time so that the powder can all be burnt before your BCG attempts to extract the case and you get maximum charge without destroying your case.

I’m not aware of any low pressure NATO caliber the AR-10 has been chambered in.

7.62x51 NATO certainly isn’t a low pressure cartridge/chambering.

Gas tube length will have little, if any effect on bolt lock time unless you really increase the volume.

Port pressure, port diameter, and plug dwell time will have much more effect on bolt lock time.

Port pressure can be controlled with port location from the chamber, as well as propellant and projectile combinations.

The powder is already burned within a few inches from the chamber, otherwise gas tubes would be clogged, along with the internal expansion chamber between the bolt and carrier. You would have fiery particles of powder shooting out from the gas vents on the carrier as well. Powder is fully converted in the chamber area for the most part due to volume, pressure, and temperature. The nitrated pulp can’t stay below its flash point under those conditions, so it burns in a tiny fraction of a second before the projectile has even traveled much past the throat.

If you’re talking about getting the most of the cartridge potential with specific loads, then ELGS with mechanical advantage adjustable gas balanced against reciprocating mass and spring weights are a place to look first.

Do you have a current rifle that isn’t doing what you want or is this more of a theoretical solution for tweaking the gas system?

 

[Kocher]

Running a A.R. 10 6.5 Creedmoor 22 inch barrel with a +2 gas system and adjustable gas block. h2 buffer, All are Precision Aero upper lower.

I wanted to see if there was a fix to some of the issues that I’ve seen including my current issue with a 22 Creedmoor on the A.R. 10.
The brass life has not been good even at light loads.
it is possible that the powder or it’s nosler brass I’m using is just not a good one.

I would think this would be able to tolerate at least the normal amounts of powder that would be comparable to the 6 mm and 6.5 Creedmoor.
This is a bit of a wild cat so perhaps that’s where my issue stands but listening to others that had 6 mm &6.5 Creedmoor ran into issues with case life.

I should just post:
anybody had success with 6 mm and 6.5 Creedmoor running stock configuration with stock amounts of powder?

 

[Kocher]

I’m not aware of any low pressure NATO caliber the AR-10 has been chambered in.

7.62x51 NATO certainly isn’t a low pressure cartridge/chambering.

Gas tube length will have little, if any effect on bolt lock time unless you really increase the volume.

Port pressure, port diameter, and plug dwell time will have much more effect on bolt lock time.

Port pressure can be controlled with port location from the chamber, as well as propellant and projectile combinations.

The powder is already burned within a few inches from the chamber, otherwise gas tubes would be clogged, along with the internal expansion chamber between the bolt and carrier. You would have fiery particles of powder shooting out from the gas vents on the carrier as well. Powder is fully converted in the chamber area for the most part due to volume, pressure, and temperature. The nitrated pulp can’t stay below its flash point under those conditions, so it burns in a tiny fraction of a second before the projectile has even traveled much past the throat.

If you’re talking about getting the most of the cartridge potential with specific loads, then ELGS with mechanical advantage adjustable gas balanced against reciprocating mass and spring weights are a place to look first.

Do you have a current rifle that isn’t doing what you want or is this more of a theoretical solution for tweaking the gas system?

I appreciate your input from all.

I believe the NATO 30 caliber is a lower charge of powder compared to 308.
charge don’t have one so I can only go by what I’ve heard as for this reason people go and buy the “high pres. bolt” for the other calibers used in the ar10.

is it just because generation X needs to know the “Why” what does my set up have anything to do with my question?
So I guess in many ways it’s theorizing or try and understand how the whole A.R. 10 works and what types of things can increase the lock time. I think the answer I received is a pretty good one as far as how it works and helps me understand and perhaps try and void much frustration.

my goal is to have a varmint rifle semi auto that’s accurate, bucks the wind and has nice case life to reload.
so far I have not found that.

So far I’ve not been successful with A.R. 10 platform in the 22 Creedmoor

how is the 6 mm Creedmoor package working for most?

 

[LRRPF52]

I appreciate your input from all.

I believe the NATO 30 caliber is a lower charge of powder compared to 308.
charge don’t have one so I can only go by what I’ve heard as for this reason people go and buy the “high pres. bolt” for the other calibers used in the ar10.

is it just because generation X needs to know the “Why” what does my set up have anything to do with my question?
So I guess in many ways it’s theorizing or try and understand how the whole A.R. 10 works and what types of things can increase the lock time. I think the answer I received is a pretty good one as far as how it works and helps me understand and perhaps try and void much frustration.

my goal is to have a varmint rifle semi auto that’s accurate, bucks the wind and has nice case life to reload.
so far I have not found that.

So far I’ve not been successful with A.R. 10 platform in the 22 Creedmoor

how is the 6 mm Creedmoor package working for most?

The “high pressure” bolts are really "small firing pin aperture" bolts. It has little to do with peak chamber pressure.

When you reduce the bore volume with the overbore cartridges like any of the 6.5-08 class or smaller (.257, 6mm, and .224), it increases the length of the pressure curve so that primers start to flow into the void on more generous firing pin aperture bolts.

If you want a varmint semi-auto, I would walk away from the AR-10 and step into an AR-15 chambered in .224 AR, .224 Valkyrie, 6mm ARC, or 6.5 Grendel (shooting 85-100gr varmint bullets).

Your barrel life in an AR-10 chambered in 6 or 22 Creed will be low, and you have to deal with that reciprocating mass and sight picture with more rifle mass/weight than is needed for effective varmint-shooting.

With an AR-15, there are less headaches and they’re easier to shoot, especially in the recommended chamberings.

 

[Forrest]

Adjustable Gas Block!