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L Haney
November 19, 2016, 17:19
Between a carbine and full length gas tube. Swapping a barrel right now and the one I got is too short to fit the new barrel. Shit.

Phucked up thing is they are both 16" barrels.

Gotta' love standards, there are so many to chose from.

Andy the Aussie
November 19, 2016, 17:21
Sounds like you have a mid-length (right between a carbine and standard AR length) mate. Though I am no AR 'spurt either.

L Haney
November 19, 2016, 17:22
Sounds like you have a mid-length (right between a carbine and standard AR length) mate. Though I am no AR 'spurt either.

So there's THREE of the damned things?

ETA: Gas port is 9.5 inches from the front of the receiver on the new barrel.

meltblown
November 19, 2016, 17:29
Full length is the original Stoner 20" barrel design. Mid sits back about mid way between a carbine. A mid will work on a 16" barrel. Not so full length. Only about 2" before the muzzle. I use mid on 16 only because I don't like carbine HGs. With a mid you can use longer HGs and use the longer sight radius if you are using a gb sight combination.

L Haney
November 19, 2016, 17:34
A mid will work on a 16" barrel.

Apparently not all 16" barrels. Hence my funk.

meltblown
November 19, 2016, 18:00
Apparently not all 16" barrels. Hence my funk.

Mid and carbine are used on 16" barrels. Got some copper tubing to get you by till the gas tube arrives:tongue: I only have 1 AR. It shoots Russian junk.

My thought is that carbine GBs are for short barrels that will cost you 200. Mid is perfect if you want a longer SR if you are using irons. All that buffer stuff is on Arf

M90A1
November 19, 2016, 20:03
Ya gots to pay attention to what you're buying. ;) Barrel makers always tell you which gas system length they used on a barrel. There are at least 5 lengths in use these days, pistol, carbine, mid, intermediate, and rifle.

badzero
November 19, 2016, 20:36
The Armalite 16 inch lightwieght carbine barrels take a different Armalite only tube, it's about 1/2 an in longer than a standard carbine.

Timber Wolf
November 20, 2016, 06:21
I like the mid-length gas 16" barrels. I think the idea was the gas port is the same length from the end of the barrel as a rifle length gas port is from the end of a 20" barrel so the gas impulse is similar. The extra handguard length though is why I like them.

M90A1
November 20, 2016, 08:58
The Armalite 16 inch lightweight carbine barrels take a different Armalite only tube, it's about 1/2 an in longer than a standard carbine.

Hmmm, that sounds like a really bad idea. :confused: Better keep some replacement tubes, just in case they change their mind later and go to a standard size. :eek:

Bertellione
November 21, 2016, 23:32
Armalite isn't going to change its actually a better gas tube set up that makes the rifle much more reliable. The standard tube isn't long enough for reliability as I understand.

oleblu72
November 21, 2016, 23:49
So there's THREE of the damned things?

ETA: Gas port is 9.5 inches from the front of the receiver on the new barrel.


I have a 18" ARP barrel with a mid length gas system and it measures 9-1/4" to the gas port.

Mark

hueyville
November 22, 2016, 07:10
Finished up a mid length upper yesterday. H2 buffer and ran perfect from first round. Bought some odd 18" DSA fluted barrels with mid length gas, used curly gas tubes to lie to the rifles and simulate rifle length gas. If going to build or maintain a variety of factory built AR's suggest all have a carbine, mid and rifle length spare tube in your parts kit. I keep short curly tubes in short, carbine and mid.

Carbine length with curly gas tube:

http://i60.tinypic.com/307ni1l.jpg

dmk
November 22, 2016, 07:38
I like the mid-length gas 16" barrels. I think the idea was the gas port is the same length from the end of the barrel as a rifle length gas port is from the end of a 20" barrel so the gas impulse is similar. The extra handguard length though is why I like them. My carbines are all mid lengths too.

Even Colt has finally seen the light and now makes a carbine with a mid length gas system.

http://www.colt.com/Media/Press-Releases/articleType/ArticleView/articleId/155/Colt-Introduces-the-Colt-Combat-Unit-Carbine-Featuring-Mid-Length-Gas-System

dmk
November 22, 2016, 07:40
I keep short curly tubes in short, carbine and mid. Why do you run a curly in a midlength? Longer barrel? :?

gordonm1
November 22, 2016, 10:47
Hmm, curly gas tube... I learned something this morning but I diindo nuttin.

TenTea
November 22, 2016, 11:29
I was prepared to try one of these pigtail gas tubes in a recent pistol build, but as it turns out, the thing runs fine with a straight, pistol length gas tube on a 7.5 inch barrel.

These were the cheapest I could find in that application.
Most others were way spendy.
No experience with this company.

https://www.deltateamtactical.com/Omega-Mfg-AR-15-Pistol-Length-Spiral-Pigtail-Gas-Tube-USA-MADE_p_4420.html

hueyville
November 22, 2016, 15:46
Lies to the rifle and tells it is rifle length gas slowing impulse a tad. Like my rifles to run slow and soft. Pistol length always gets them, carbine usually gets them, mid length sometimes gets them. Got a batch of 18" barrels all with carbine gas in a bargain deal and those all got them. The two Slidefires from this picture were built exactly the same except one got a straight gas tube with full gas plus stock carbine spring and buffer. The other got a curly tube, adjustable gas, Tubbs Flatwire Spring, H2 buffer and a suppressor mount. (wanted option of tuning if decided to put a can on bump fire rifle)

Without a can the the curly tube with other upgraded parts runs softer and slower than the straight tube with full gas. The straight gas with all milspec parts runs fine and not enough difference to tear it down and change it. Why I like DI AR's and not interested in pistons. If assembled correctly worst case is a change in buffer weight to tune a rifle to how a person prefers it to run. Almost 4:00 pm, gotta go light up the range so we can clock out on time.

Bladewurk
November 22, 2016, 19:09
I avoid pigtails, they seem to fail at a much higher ( earlier) rate. Maybe its the stress in that coil but they seem to want to pull right out of the gas block when hot. LMT believes the gas tube on DI guns should be as straight as possible, a claimed benefit of the MRP and MWS gas tube design. That gas tube will get glowing red hot after just 4 mags " bumped" or Auto at the cyclic rate..

ratas calientes
November 23, 2016, 20:21
So there's THREE of the damned things?

ETA: Gas port is 9.5 inches from the front of the receiver on the new barrel.

I count four.

Rifle
Mid
Carbine
Pistol
:D

M90A1
November 23, 2016, 21:39
I count four.

Rifle
Mid
Carbine
Pistol
:D

Nope, I stated five earlier, but it looks like there might be six. Granted, the intermediate and the KAC are going to be rare, and I'm not even sure about the KAC length existing. I thought the intermediate was a KAC thing, but I guess there could be another. Hell, with the Armalite mentioned above, there could be seven.

Read through this post.

http://www.ar15.com/forums/t_3_12/704471_.html

ratas calientes
November 24, 2016, 02:01
Nope, I stated five earlier, but it looks like there might be six. Granted, the intermediate and the KAC are going to be rare, and I'm not even sure about the KAC length existing. I thought the intermediate was a KAC thing, but I guess there could be another. Hell, with the Armalite mentioned above, there could be seven.

Read through this post.

http://www.ar15.com/forums/t_3_12/704471_.html

You got me.

Greensborobob
November 24, 2016, 06:52
As stated earlier the barrel will specify which gas tube length to use, but you also need coordinate the handguard length if not using a free float.

W.E.G.
November 24, 2016, 08:24
I've been contemplating why I ever thought I "needed" a carbine-length AR.

I guess I just not interested in being cool anymore.

Decided my goal is two lowers, and three 20" uppers. Mostly to be used in rotation, so that the freshest upper is in play beginning mid-June.

After many years, I've found no practical use for the shorter uppers. Probably going to send them away before long.

Mebsuta
November 24, 2016, 08:31
I just figured I was too dumb to 2nd guess the guy who designed teh AR-15, so I stayed with 20-inch rifels.

M90A1
November 24, 2016, 08:52
I've been contemplating why I ever thought I "needed" a carbine-length AR.

I guess I just not interested in being cool anymore.

Decided my goal is two lowers, and three 20" uppers. Mostly to be used in rotation, so that the freshest upper is in play beginning mid-June.

After many years, I've found no practical use for the shorter uppers. Probably going to send them away before long.

If your only use for an AR is to shoot NRA competition, I see your point.

Timber Wolf
November 24, 2016, 09:19
[QUOTE=Bladewurk;4329360]I avoid pigtails, QUOTE]

My only experience with a pigtail gas tube was on a carbine I bought cheaply from a bud because he could not get it to run. All I did was replace the pigtail with a regular tube and it ran fine. Soft is good, but actually working is better.:)

Barbcue
November 25, 2016, 21:36
If ya need gas tubes theres a guy goes by "hochimin" on ar15.com that has some sort of connection to Spikes overruns or something and has discounted Spikes Tactical MELONITED gas tubes in carbine and midlenght..

I bought a few for a couple of midlength gas PSA PA-10 builds and they looked nice as hell and heavy duty they were 17 bucks each but imo after handling one worth it !..i won't use any other in future builds if i can help it..

hkshooter
November 25, 2016, 21:57
I guess I just not interested in being cool anymore.



You were looking cool in the rear view mirror of the Camaro 25 years ago, Gary. :tongue::rofl:

I never tried to justify a carbine length AR, just would up with one. I actually prefer a full 20" barrel for the caliber first and short barrels second. However, I've got rid of every AR I've ever had, they just don't seem to stay around.
Today I've acquired another but for a specific reason, it's inexpensive and I don't care what happens to it. Yeah, it's light and I can carry more rounds. Meh. For less than $1000 including the 1.5x4 Leupold and it's mount I'm well armed and if the rifle gets broke, beat up, rusted, busted, or gone, I'll be much less heart broken than if it happened to an HK or FAL.
Disposable rifle.

AR's. They got no soul.

NFADLR
November 25, 2016, 22:43
Since barrels are akin to gas tubes via DI, Can a 18 inch stainless steel AR barrel use both DI and a piston system or are they two separate things ?

I'm sure there is a ratio of handguard coverage on a 18 inch barrel that is equal to the coverage of a 20 inch barrel ?

The point is I want more coverage in my soon to be found 18 inch stainless steel barrel than the carbine length provides as well would like a better gas or piston system length than the carbine length offers.

M90A1
November 25, 2016, 22:59
Since barrels are akin to gas tubes via DI, Can a 18 inch stainless steel AR barrel use both DI and a piston system or are they two separate things ?

I'm sure there is a ratio of handguard coverage on a 18 inch barrel that is equal to the coverage of a 20 inch barrel ?

The point is I want more coverage in my soon to be found 18 inch stainless steel barrel than the carbine length provides as well would like a better gas or piston system length than the carbine length offers.

Don't understand your first question, but if you don't want an 18" barrel with the carbine gas system, just buy one with the mid or rifle system. There are also piston systems available in all three lengths. So, just look around until you find the barrel you want. Regular handguards are available for whichever length gas system you choose. Free-floats are available in any length you want. Sorry if I completely missed your point.

Here's one for a rifle length gas system:

http://www.gmriflebarrel.com/gm-m18-18-223-wylde-chamber/

Here's one for a mid length gas system:

http://www.brownells.com/rifle-parts/barrel-parts/rifle-barrels/ar-15-m16-match-barrels-18-mid-length-spr-barrel-sku100-009-961-54526-104736.aspx